40 amp covers the majority of motors in use with a small margin, so maximises it's suitability. It also matches the cells well. I'm sure UPP read the cell testing reviewsInteresting. Seems the battery BMS rating is almost spot on for keeping it at optimum performance.
Yes I was interested in how they decided on using 40a BMS in the battery, it's as if they knew that it was the optimum limit, although if the cell rating was actually good at 10a, the BMS could've been higher in theory?
Either way, based on the info I've received, I'll keep the controller at 35a.