So, what I wanted to do is: we bought a new domain and want all players to connect with our new one. if someone joins with the old one, I want it to kick them and say'connect with the new IP - play.blahblah.net' is this possible ? how can I do this?
There is a ServerAddress field in clientData. I think that's what you're looking for. https://github.com/pmmp/PocketMine-MP/issues/488#issuecomment-290745879
Yes that's what i meant, but according to some other people claims they will only show the IP not the hostname afaik that is, but worth a try after all this updates maybe...
It's on the same server, so it's pointless to transfer them. He just wants to force players to change the hostname they use.