For sure that's a possibility now.
Not for SBD, we want those to drop in value.
But delegating STEEM challenge rewards may be a good idea. It will probably lower participation though, so it's up to the one who runs it to decide.
It's great that you brought it up, most probably didn't even think about the possibility.
Thank you pharesim! I hope you guys will consider this post as a potential idea on how to improve the platform and the reward!