I might think it's a bit early to have it fully develop and manifest, I'm not about to object because it would be non-canon.

That being said, I also don't see a problem with people keeping characters in a mostly-canon state, either. For one thing I plan to have no real changes happen with Kino or Kyouko. Sure, new experiences and learning new things, but no serious emotional shifts. Or physical changes, on account of the fact that everyone's going to be restored to their base state no matter what happens at the end of a challenge, and "refreshed" to avoid fatigue or worse.

As for abilities, nothing I particularly want for Kyouko, and part of why Kino's awesome is she's a totally normal person who nonetheless can pull off some pretty crazy things.

To put it simply, I have no objection to anyone having characters go through major changes, but it also doesn't mean everyone has to do it.