No / Maybe
I'm guessing that this might be an unpopular opinion, but I thought I'd bring it up.
As much as I agree that a massive effort is put into writing good challenges and they should be rewarded more, this would also go the other way. The problem is generally stated herehere, trivial questions generally get flooded with up-votes especially with help from HNQ.
I'd say the best solution is instead of changing the reputation awarded for questions, is to switch the focus to using question votes more effectively. By this I mean, upvoting what you feel is a high-quality, good challenge, rather than a challenge simply because it's easy.
My point is, as much as I do agree high-quality challenges should be rewarded more, this would also affect trivial challenges significantly also, with a single upvote requiring 5 downvotes to counter. So my proposal is:
No, unless downvotes are worth much more