How does everything hold up to the added stress on the driveline?

I had a summit for awhile and it was fun as a dedicated crawler but now bought a revo roller to turn brushless. I want to have it be mostly based as a heavy duty offroader so wondering if the summit is a better base than the erbe.

How do the locking diffs work under brushless power? (assuming you dont try to engage them while under power).

I am mostly thinking the 2 speed would be most beneficial so when trying to crawl on log piles and such I can run 1st so the final drive is a lot higher and I can utilize the torque better. I am planning on running 7-7.5 inch tall tires (3-3.5 wide). so slightly taller than canyons but also more narrow.

Thoughts? Should I just throw the LT and 2 speed on the erbe and call it a day or would the summit be a better base truck to build off of?

I do want to be able to throw some standard mt tires on the truck (or even truggy tires for the track) and blast around on 6s for high speed bashing.