In past patches of JJ2+ (4.xx and older), it was possible for a server to change the position of a client by sending the UDP packet 0x02 that is responsible for player status updates. This functionality no longer works in current versions (because of an attempt to fix 3hk's on 4.xx days as I heard?). The real fix of 3hk's was introduced in patch 5.7 acording to the JJ2+ readme. This transportation functionality opens lots of possibilities for custom servers that doesn't support mutators or servers that uses 3rd party programs and I don't see any reason/risk leads to disable this funtionality.

So, can we have this functionality restored when joining servers hosted on vanilla or versions older than 5.1?

If there is a concern that restoring trasportation will cause other problems, then can we have a custom UDP packet (a copy of packet 0x02 but with different ID) that whenever a client receives, it will trigger the trasportation, and keep the original 0x02 like how it is currently?

I don't know how much effort needed to acomplish this, but my guess it's just a simple "if condition" that checks wheather the player is local or not and according to that, the game will/will not change player position. I found this info while I was browsing plus.dll assembly at address "plus.dll+CB37F"

Thanks!