1/12th at 21.5 would be way too slow. Everyone is evenly matched for speed right now and there are several new drivers this season at CC doing quite well. The cost of 1/12th is far lower as a whole compared to touring cars also...neither do I see guys switching motors but once or twice a year...doesn’t seem to be the same motor-of-the-month issue as tc. Remember, we are only at half the voltage as well. I think moving 1/12th to 21.5 would actually lose drivers.
Another good example of the success of 17.5 1/12th is NORA this season. About five rookie drivers...all making good laps and learning their cars.