(The post in this thread I intended to reply to seems to have been deleted. So I'll add the reply to it I wrote anyway, in case the info is useful to someone.)
"Not currently, but this evening I finished implementing a patch to bypass specific basic objectives that have been cause for concern, and remove their completion XP reward.
Fresh from the oven so needs to go through review, QA and release candidate testing, though.
To clarify, is it specifically the Basic Combat and/or Basic Prayer challenge you want to bypass?
And basic challenges don't expire, so unfortunately, no, waiting it out isn't currently an option."