So one of the things we have on Eldritch is "Player Experience". This is our nod to people who help the game by running scenes, the award that they get some XP for participating but the extra award is that they get to spend it on any character that they play. It should be a lot easier than watching people transferring XP from PC to PC, and calculating how many, and etc. etc.
So we set up an Alts Registration System. ARS is mostly a way to verify that one alt belongs to another and is entirely optional. In small part it helps staff check alt limits, but it's mostly meant for players to use:
xp/convert, the system that converts Player Experience earned from running scenes to Normal Experience, which is the raw pool each character uses to buy nearly everything.
I can't say it was easier to set up than a way to regulate converting XP from one alt to another, but it's our way. I hope that it gets good use.