Best not to risk it? I probably will try to sign up on the early side too (don't you need to show that you've graduated though? Also it looks like they recommend having completed one postgraduate year of training, but I don't know if they hold anyone to that).
Sorry guys, I chickened out an in the end didn't cancel any interviews. It's such an unpredictable year that after consulting with family I decided a bit of a buffer was a good idea. Per specialty recommendations for average applicants based on numbers, I only applied to 15 programs. I was offered 12 interviews and initially was only going to attend 10 (not a competitive specialty) but changed my mind and am going to all 12. The 2 I was on the fence about were both prelim programs, and it seems like every year there are people who match advanced programs but not prelims and would be grateful if those spots end up in SOAP (though my guess is that this year they won't, but we'll see). Not trying to kick off the whole "what constitutes hoarding" debate again, just recognizing this is a stressful time and hoping for the best for everyone.