Change "of your maximum experience" to of your Pokémon's max HP
As far as I experimented, once you enter a floor, leaving it will deny you from coming back into the said floor, so the red highlighted part shouldn't be possible.
So the best thing to do in that situation is to enter the lowest floor you can and beat all 10 Trainers.
With a full team it won't deny you a floor if your levels aren't messed up, and allows your Sweeper to gain a few extra levels for the next tougher floors.
I must have been drunk nvm lol !
Btw it's cool to see this guide of yours and Leeluckya's one ! It changes from the crybabies that spit on the August 1st EXP Update DAY 1 without exploring these new Trainer Towers offered to us, which turn out to be really Pog.