Can't use TypeAlias with aliased object's children

[thecheatah]

When trying to do the following, I get an error Operator function '==' requires the types 'OtherParticipant' and 'ChatParticipant' be equivalent. The following compiles if I use \OtherParticipant.$id. The ModelAlias OtherParticipant no longer matches \OtherParticipant.$user.$id's model ChatParticipant.

    final class MeAsAParticipant: ModelAlias {
      static let name: String = "me_as_a_participant"
      let model = ChatParticipant()
    }
    final class OtherParticipant: ModelAlias {
      static let name: String = "other_participant"
      var model = ChatParticipant()
    }

    return User.query(on: db)
      .join(OtherParticipant.self, on: \User.$id == \OtherParticipant.$user.$id)
      .all()