Silvercans in F1's with stock gearing work fine, I know from experience .. the issues arise with melting motors and overheating stock esc's when you move away from kit gearing too 64dp / 48dp and gear them to high, hence the current draw increases ...
If an F1 is melting motors chances are it is over geared and the driver is cheating
If they are left stock and geared out the box the speed is comparable to 13.5 tourers and the mardave running in the class.
Scott.