diff --git a/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet6_0.verified.txt b/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet6_0.verified.txt
index 4612db9d9..a8350c3f3 100644
--- a/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet6_0.verified.txt
+++ b/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet6_0.verified.txt
@@ -1277,19 +1277,13 @@ namespace DynamicData
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector)
             where TObject :  notnull
             where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.Reactive.Concurrency.IScheduler? scheduler = null)
-            where TObject :  notnull
-            where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? interval = default)
-            where TObject :  notnull
-            where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.Reactive.Concurrency.IScheduler scheduler)
             where TObject :  notnull
             where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval)
             where TObject :  notnull
             where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval, System.Reactive.Concurrency.IScheduler? scheduler)
+        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval = default, System.Reactive.Concurrency.IScheduler? scheduler = null)
             where TObject :  notnull
             where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval, System.Reactive.Concurrency.IScheduler scheduler)
diff --git a/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet7_0.verified.txt b/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet7_0.verified.txt
index 10b8258c4..0f790bb5c 100644
--- a/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet7_0.verified.txt
+++ b/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet7_0.verified.txt
@@ -1277,19 +1277,13 @@ namespace DynamicData
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector)
             where TObject :  notnull
             where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.Reactive.Concurrency.IScheduler? scheduler = null)
-            where TObject :  notnull
-            where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? interval = default)
-            where TObject :  notnull
-            where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.Reactive.Concurrency.IScheduler scheduler)
             where TObject :  notnull
             where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval)
             where TObject :  notnull
             where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval, System.Reactive.Concurrency.IScheduler? scheduler)
+        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval = default, System.Reactive.Concurrency.IScheduler? scheduler = null)
             where TObject :  notnull
             where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval, System.Reactive.Concurrency.IScheduler scheduler)
diff --git a/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet8_0.verified.txt b/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet8_0.verified.txt
index 492b4274f..af6583a04 100644
--- a/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet8_0.verified.txt
+++ b/src/DynamicData.Tests/API/ApiApprovalTests.DynamicDataTests.DotNet8_0.verified.txt
@@ -1277,19 +1277,13 @@ namespace DynamicData
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector)
             where TObject :  notnull
             where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.Reactive.Concurrency.IScheduler? scheduler = null)
-            where TObject :  notnull
-            where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? interval = default)
-            where TObject :  notnull
-            where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.Reactive.Concurrency.IScheduler scheduler)
             where TObject :  notnull
             where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval)
             where TObject :  notnull
             where TKey :  notnull { }
-        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval, System.Reactive.Concurrency.IScheduler? scheduler)
+        public static System.IObservable<System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this DynamicData.ISourceCache<TObject, TKey> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval = default, System.Reactive.Concurrency.IScheduler? scheduler = null)
             where TObject :  notnull
             where TKey :  notnull { }
         public static System.IObservable<DynamicData.IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(this System.IObservable<DynamicData.IChangeSet<TObject, TKey>> source, System.Func<TObject, System.TimeSpan?> timeSelector, System.TimeSpan? pollingInterval, System.Reactive.Concurrency.IScheduler scheduler)
diff --git a/src/DynamicData.Tests/Cache/ExpireAfterFixture.cs b/src/DynamicData.Tests/Cache/ExpireAfterFixture.cs
index 7fb27b4e1..38dfe3cac 100644
--- a/src/DynamicData.Tests/Cache/ExpireAfterFixture.cs
+++ b/src/DynamicData.Tests/Cache/ExpireAfterFixture.cs
@@ -29,7 +29,7 @@ public ExpireAfterFixture()
     [Fact]
     public void CanHandleABatchOfUpdates()
     {
-        var remover = _source.ExpireAfter(p => TimeSpan.FromMilliseconds(100), _scheduler).Subscribe();
+        var remover = _source.ExpireAfter(p => TimeSpan.FromMilliseconds(100), scheduler: _scheduler).Subscribe();
         const int size = 100;
         var items = Enumerable.Range(1, size).Select(i => new Person($"Name.{i}", i)).ToArray();
 
@@ -65,7 +65,7 @@ public void ComplexRemove()
         var items = Enumerable.Range(1, size).Select(i => new Person($"Name.{i}", i)).ToArray();
         _source.AddOrUpdate(items);
 
-        var remover = _source.ExpireAfter(RemoveFunc, _scheduler).Subscribe();
+        var remover = _source.ExpireAfter(RemoveFunc, scheduler: _scheduler).Subscribe();
         _scheduler.AdvanceBy(TimeSpan.FromMilliseconds(5010).Ticks);
 
         _source.Count.Should().Be(60, "40 items should have been removed from the cache");
@@ -85,7 +85,7 @@ public void Dispose()
     [Fact]
     public void ExpireIsCancelledWhenUpdated()
     {
-        var remover = _source.ExpireAfter(p => TimeSpan.FromMilliseconds(100), _scheduler).Subscribe();
+        var remover = _source.ExpireAfter(p => TimeSpan.FromMilliseconds(100), scheduler: _scheduler).Subscribe();
 
         _source.Edit(
             updater =>
@@ -106,7 +106,7 @@ public void ExpireIsCancelledWhenUpdated()
     [Fact]
     public void ItemAddedIsExpired()
     {
-        var remover = _source.ExpireAfter(p => TimeSpan.FromMilliseconds(100), _scheduler).Subscribe();
+        var remover = _source.ExpireAfter(p => TimeSpan.FromMilliseconds(100), scheduler: _scheduler).Subscribe();
 
         _source.AddOrUpdate(new Person("Name1", 10));
 
diff --git a/src/DynamicData.Tests/Cache/TimeExpiryFixture.cs b/src/DynamicData.Tests/Cache/TimeExpiryFixture.cs
index 6651deb10..3fb7d6c84 100644
--- a/src/DynamicData.Tests/Cache/TimeExpiryFixture.cs
+++ b/src/DynamicData.Tests/Cache/TimeExpiryFixture.cs
@@ -27,7 +27,7 @@ public TimeExpiryFixture()
 
         _cache = new SourceCache<Person, string>(p => p.Key);
         _results = new ChangeSetAggregator<Person, string>(_cache.Connect());
-        _remover = _cache.ExpireAfter(p => TimeSpan.FromMilliseconds(100), _scheduler).Subscribe();
+        _remover = _cache.ExpireAfter(p => TimeSpan.FromMilliseconds(100), scheduler: _scheduler).Subscribe();
     }
 
     [Fact]
@@ -52,7 +52,7 @@ public void AutoRemove()
         var items = Enumerable.Range(1, size).Select(i => new Person($"Name{i}", i)).ToArray();
         _cache.AddOrUpdate(items);
 
-        var xxx = _cache.ExpireAfter(RemoveFunc, _scheduler).Subscribe();
+        var xxx = _cache.ExpireAfter(RemoveFunc, scheduler: _scheduler).Subscribe();
         _scheduler.AdvanceBy(TimeSpan.FromSeconds(5).Ticks);
 
         _scheduler.AdvanceBy(TimeSpan.FromSeconds(5).Ticks);
diff --git a/src/DynamicData/Cache/ObservableCacheEx.cs b/src/DynamicData/Cache/ObservableCacheEx.cs
index 06676ef97..7bd76f3de 100644
--- a/src/DynamicData/Cache/ObservableCacheEx.cs
+++ b/src/DynamicData/Cache/ObservableCacheEx.cs
@@ -1187,6 +1187,22 @@ public static IObservable<IChangeSet<TObject, TKey>> EditDiff<TObject, TKey>(thi
         return new EditDiffChangeSetOptional<TObject, TKey>(source, keySelector, equalityComparer).Run();
     }
 
+    /// <summary>
+    /// Ensures there are no duplicated keys in the observable changeset.
+    /// </summary>
+    /// <param name="source"> The source change set.</param>
+    /// <typeparam name="TObject">The type of the object.</typeparam>
+    /// <typeparam name="TKey">The type of the key.</typeparam>
+    /// <returns>A changeset which guarantees a key is only present at most once in the changeset.</returns>
+    public static IObservable<IChangeSet<TObject, TKey>> EnsureUniqueKeys<TObject, TKey>(this IObservable<IChangeSet<TObject, TKey>> source)
+        where TObject : notnull
+        where TKey : notnull
+    {
+        source.ThrowArgumentNullExceptionIfNull(nameof(source));
+
+        return new UniquenessEnforcer<TObject, TKey>(source).Run();
+    }
+
     /// <summary>
     /// Signal observers to re-evaluate the specified item.
     /// </summary>
@@ -1429,58 +1445,6 @@ public static IObservable<IChangeSet<TObject, TKey>> ExpireAfter<TObject, TKey>(
         return new TimeExpirer<TObject, TKey>(source, timeSelector, pollingInterval, scheduler).ExpireAfter();
     }
 
-    /// <summary>
-    /// Automatically removes items from the cache after the time specified by
-    /// the time selector elapses.
-    /// </summary>
-    /// <typeparam name="TObject">The type of the object.</typeparam>
-    /// <typeparam name="TKey">The type of the key.</typeparam>
-    /// <param name="source">The cache.</param>
-    /// <param name="timeSelector">The time selector.  Return null if the item should never be removed.</param>
-    /// <param name="scheduler">The scheduler to perform the work on.</param>
-    /// <returns>An observable of enumerable of the key values which has been removed.</returns>
-    /// <exception cref="ArgumentNullException">source
-    /// or
-    /// timeSelector.</exception>
-    public static IObservable<IEnumerable<KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this ISourceCache<TObject, TKey> source, Func<TObject, TimeSpan?> timeSelector, IScheduler? scheduler = null)
-        where TObject : notnull
-        where TKey : notnull => source.ExpireAfter(timeSelector, null, scheduler);
-
-    /// <summary>
-    /// Automatically removes items from the cache after the time specified by
-    /// the time selector elapses.
-    /// </summary>
-    /// <typeparam name="TObject">The type of the object.</typeparam>
-    /// <typeparam name="TKey">The type of the key.</typeparam>
-    /// <param name="source">The cache.</param>
-    /// <param name="timeSelector">The time selector.  Return null if the item should never be removed.</param>
-    /// <param name="interval">A polling interval.  Since multiple timer subscriptions can be expensive,
-    /// it may be worth setting the interval .
-    /// </param>
-    /// <returns>An observable of enumerable of the key values which has been removed.</returns>
-    /// <exception cref="ArgumentNullException">source
-    /// or
-    /// timeSelector.</exception>
-    public static IObservable<IEnumerable<KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this ISourceCache<TObject, TKey> source, Func<TObject, TimeSpan?> timeSelector, TimeSpan? interval = null)
-        where TObject : notnull
-        where TKey : notnull => ExpireAfter(source, timeSelector, interval, Scheduler.Default);
-
-    /// <summary>
-    /// Ensures there are no duplicated keys in the observable changeset.
-    /// </summary>
-    /// <param name="source"> The source change set.</param>
-    /// <typeparam name="TObject">The type of the object.</typeparam>
-    /// <typeparam name="TKey">The type of the key.</typeparam>
-    /// <returns>A changeset which guarantees a key is only present at most once in the changeset.</returns>
-    public static IObservable<IChangeSet<TObject, TKey>> EnsureUniqueKeys<TObject, TKey>(this IObservable<IChangeSet<TObject, TKey>> source)
-        where TObject : notnull
-        where TKey : notnull
-    {
-        source.ThrowArgumentNullExceptionIfNull(nameof(source));
-
-        return new UniquenessEnforcer<TObject, TKey>(source).Run();
-    }
-
     /// <summary>
     /// Automatically removes items from the cache after the time specified by
     /// the time selector elapses.
@@ -1497,7 +1461,11 @@ public static IObservable<IChangeSet<TObject, TKey>> EnsureUniqueKeys<TObject, T
     /// <exception cref="ArgumentNullException">source
     /// or
     /// timeSelector.</exception>
-    public static IObservable<IEnumerable<KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(this ISourceCache<TObject, TKey> source, Func<TObject, TimeSpan?> timeSelector, TimeSpan? pollingInterval, IScheduler? scheduler)
+    public static IObservable<IEnumerable<KeyValuePair<TKey, TObject>>> ExpireAfter<TObject, TKey>(
+            this ISourceCache<TObject, TKey> source,
+            Func<TObject, TimeSpan?> timeSelector,
+            TimeSpan? pollingInterval = null,
+            IScheduler? scheduler = null)
         where TObject : notnull
         where TKey : notnull
     {