Use cogflies, but save them for the later/problematic parts of the gauntlet (such as the big guys).
Golden guys cannot throw theirs directly under themselves.
Faster heal and claw mirror(AoE one) for blue slots
big guy floor clearer is fairly safe to damage them on iirc

Rent to own skeleton

Repelling blast has been insanely good to me. Stage hazards or no, pushing shit is stupidly useful.

If they need to do math to win chances are they're probably better off restarting the run for something better anyway.