My husband was granted two years in the support group in April 2012, then in 2014 we heard nothing so he was obviously deferred for two years. Then in early Feb this year he was sent the renewal forms to fill in. So it looks like they're promptly getting to the ones who were deferred. Be as ready as you can with filling in paperwork.
He's also been sent an appointment for a face to face this time, whereas last time he was put in Support group just on paperwork alone. As he's got even more wrong with him by now we were surprised they sent for him, so maybe they're trying to see the ones who have never been seen.