I don't think we will have any issue here, particularly with Jayvin through to the next round (he is bound to be the most difficult one to coordinate moving timelines with, which makes it a massive headache and is not fair on him to single him out unnecessarily).
I wouldn't bring stuff forward to the point the second round question is also brought forward without everyone being aware. As far as he is concerned he need not log in until Wednesday noon. We can't keep waiting for everyone to be on board everytime something gets changed either. It's not fair on you for starters. 24-12-12 sounds reasonable to me though. 24 hours for the question, research and voting, then whoever got blocked knows over the next day they need to log in twice. Not a big ask, so long as it is set.