Long story short, I have a friend who transferred to Spriggan and has been subject to ongoing harassment from some players. The blacklist and reports are only going so far but their experience of being on the world/datacenter now just makes them then want to leave altogether, though obviously they can't because of the restriction. An in-game GM told them it's currently not possible to bypass or reduce the 90 day restriction, so for the time being they'll have to deal with it the best they can until the duration has passed, and then they can look at moving to a different world.
They would like to suggest for the developers to consider implementing a one-time only (per account) service that let's a player currently under a restriction to be allowed to transfer to another world. If necessary to avoid sudden movements of population, the player would have to provide sufficient reasoning to an in-game GM first and if they accept, the character is flagged to be allowed to use the transfer service again. The service would also only be limited to players who transferred to the restricted world to begin with, so new characters would not be allowed to take advantage of this (as they could just make a new character on a different world anyway without losing much).
*The GM said to post feedback/suggestions in the forums and my friend is banned from here (incase anyone is wondering), hence why they could not come to do it themselves.