Messages in conversations can be reported, which cannot be seen by the other conversation participants.
The whole content of the reported message is included in the report.
You can either delete a single message out of a conversation (if you have the permission to do so) or delete a whole conversation with all messages (uncommonly called "leave conversation and ignore further messages" in XenForo).
So it be only the search, the reading-confirmation and the message quota which is not available in XenForo.
But the first two are already covered in add-ons.
As you see, all you want is there. You just need to change a few phrases (I think there were about 30 of them I've changed for our users) to make the transition much easier. After your users are used to it, they won't go back to the old system.
The whole content of the reported message is included in the report.
You can either delete a single message out of a conversation (if you have the permission to do so) or delete a whole conversation with all messages (uncommonly called "leave conversation and ignore further messages" in XenForo).
So it be only the search, the reading-confirmation and the message quota which is not available in XenForo.
But the first two are already covered in add-ons.
As you see, all you want is there. You just need to change a few phrases (I think there were about 30 of them I've changed for our users) to make the transition much easier. After your users are used to it, they won't go back to the old system.