Griefing is literally the norm on every high pop pvp server anyways. Big pvp tribes hop servers chasing fights from one server to the next and don’t even stay on these servers long term. So take away fast leveling but give a limited server invasion mechanic for limited pvp. Likewise wanting to do PVE stuff on a different map shouldn’t require a permanent presence either. Full player transfers though just mean Ark style hordes taking over servers. Doesn’t even matter if you put a transfer timer on, people have level 60 characters all over the place. You will have 40 people sitting in a discord channel before raid waiting for the server to get knocked offline and the minute it comes back up a horde transfers in taking all player slots to offline as many bases as possible. Limiting invaders to maybe 10 at a time prevents that while forcing people to spend a month on a server to get to lvl 60 makes them commit to a home server