The OP has stated 2-3 times that he will be sticking with the rapid trip plan...fair enough....his time, his preference, his decision.
However, the challenges Grit Dog highlights (particularly if there is a breakdown, big flat to change, uncertain parts availability, etc), while certainly not insurmountable or any real problem, will have a very noticeable impact on a trip that is scheduled for X00 Miles per day.
One of the trips I made in my younger days from Los Anchorage to Idaho, I knew from experience that I could make it in slightly over 80 hours (driving a pickup and being young didn't need to sleep much). Had a flat. Nice weather, happened right next to a parking area, quick change...but even so, that quick change to the spare, plugging the flat, and then stopping to air up the repaired tire took about 4 hours all told....adding 5% to the trip duration, even though all I had to find was a tire shop in Whitehorse.
What if you have a blowout and need a new big rig tire somewhere remote? Or an RV part that is not in the local shop? Low possibility I understand, but even a minor hiccup is a few hours that aren't part of the X00 miles per day plan.