Noobie question: If the 85A is a bit light, couldn't you just use a 80 or 100 amp fuse between the ESC and the motor to keep from cooking the ESC? Maybe like these:
https://www.vtewarehouse.com/content/electromech/fuse/html/maxi/maxifuse.php
Replacing a $0.70 fuse is a lot cheaper and wouldn't...