Since the gamemode/challenge is so niche, I can't see more than a few people doing it. Adding this would be a "waste" of development time, relative to other things that can/need to be done, in my opinion.
However, like I said on a previous post, good luck with your challenge!
I totally get it. I think it might be easy to add if your just porting the newer version of the plugin from rubellite on the servers runelite.