Your source of the 24 hours is interesting. I'll stick with as soon as possible upon leaving the wilderness but nothing sanction by the government. I agree about checking in and always have as soon as I can get to station and recommend it.  I'm surprised by the number of people who claim they don't.

I get bemused by the combining of permits and RABCs, etc. Better to think of then as all separate tasks.  Crossing into Canada, Crossing into US, entering the Q,  entering the BWCAW, fishing in Ontario, fishing in Minnesota - six different governments and other than park rangers enforcing fishing, no crossover.  I remember asking a Q ranger if they wanted to see RABC on my first trip, would have thought I asked them to carry my gear.

In researching this, came upon   (You need to Login or Register; Very useful site for the potential Q traveler.

WFA is good - I'm just repeating because it's no cost this time and the repetition makes it stick a lot more.  Was I think $160.  Our Troop is paying $120/person for whomever in the troop - Scouts and Scouters - wants to take it. n Were there  not now a waiting list to outsiders, I'd offer it up here.