i rode about 6000km with normal DH Rim and MTB Tires....did not had any Problem.
on my Raptor it worked also for a few hundres kilometers. After i switched to Sabvoton Controller and used it with 100a of Regen Power ( up to 4,5KW on a Switch)
my Spokes brokes. Same Power all the Time....So if you dont want to use really Hard and High eBrakes, Normal DH Rim will be okay. Even for Offroad and some Small Jumps.
I know the Disc Brake uses the same direction and force to stop the wheel. But a Regen Switch Cuts in less 0,1 Second. Thats what i think kills the spokes.
Means theres no time to start "flexing" for the spoke.
But theres another thing what you have to think about bicycle tires.
When your on a Cro and pushing +5KW, your tire will be finish after a few hundred kilometers. To be honest; After 500km a Offroad MTB Tire has to be replaced.
I was pissed of that and put another 300km on it and burnded it down after that.
a motorcycle Tyre last 3-4 times longer and if you flat that Monster you can Probably drive home on walking speed without killing your rim.
Think About a Flatted Tyre and your 20-30km far away from home with that 50-60Kg Monster.....