[REQUEST] leave event for after the user has already been removed from the list of players

[Neptune-Sky]

Is your feature request related to a problem? Please describe.
Yes. Trying to run /execute unless entity @a[name=player] in the leave event when player leaves does not get run, as the server still thinks that they are in the server.

Describe the solution you'd like
An event such as after_leave that gets called after the user is no longer considered "in the server" would be nice for edge cases like this.

I understand the purpose of running the commands before they are actually gone as that would be the vast majority of use cases, though.

Describe alternatives you've considered
The only real alternative here would be to use command blocks, which I am using this mod specifically so I can avoid doing such.

Additional context
N/A