I must ask - why not just start a new character on a more populated world, like Bera, Reboot, etc.? What is the urgency for world transfer?
Unless you are level 200+, in such case I can understand why you wouldn't want to start over.
But considering all the events that boost Leveling up and EXP boosts, reaching level 200, by itself, isn't going to take as long as it used to be.
Besides, I suggest adding a Cash Shop item to allow world transfer individually for those who are interested, not affecting the entire world population of a certain world.