I certainly do not favor changing cells for different classes. The last thing I need to carry around ar 19T and mod packs. Now I carry 5 or 6 decent packs, with a few extra for practice, testing, etc.
Occasionally, (regionals other large draw events), I race stock and 19T.
I've often thought about having a so called restrictor plate on ESCs / motors, to limit RPM or amp draw. But, I have seen all to often in stock racing the freight train racing - especially on large open tracks. I don't think this method would be overly effective.
In the sensored / sensorless BL debate: I don't care. I race what's legal. If manufactures have a better idea, that will lower my cost, and maintain / increase performance, while reducing maintanance, talk to the sanctioning body.
I've shifted all my electric offroad stuff to BL. Sure, I've had times which I wish I had different (more) legal motor choices. But, I love taking my buggy / truck of the track and doing nothing until the next heat. Even more so, with Lipo. I've actually made entire club weekends doing nothing more than turning on power to my buggy / truck and transmitter. Now that is sweet! No motor swapping. No motor lathe. No battery maint - not even charging.
I'm only hoping ROAR and IFMAR see this huge ease of operation and allow this technology to enter mainstream. Some Naysayer’s at my LHS say this will kill new people from getting. I say BS. What's the first thing we tell newbies to do their RTRs? Get a new motor and batteries, and many of those RTRs need a new ESC to work well with better (legal) motors and batteries anyway.
Would it be really that bad, if you allowed a brushed motor / nimh RTR kit setup in the stock class, if everyone was using BL / lipo? If you get beat by that setup, then you got beat by the driver anyway.