Hi Oscar Yankee,
It depends on which seat you are. If you are an FO, don't worry
. I recently joined EZY and got my transfer to my prefered base during the ground course. And if Stansted is your first choice you'll get it in no time as it's a big base with lot of movements. Apply ASAP to your base captain by email and just wait for the good news.
As I undestand it, there are only 2 restrictions about base transfer : You can only be on one waiting list at the time and once you get a requested transfer you are base frozen for one year. But as I said I'm brand new in the company so maybe more experienced chaps could have another view.
Hope this will help you.
Regards