Pete if you have the power you want, and have the engine at a reliable tune......I wouldn't worry about it.

Generally speaking temping is just to be safe. I tune for performance and make sure i can see a thin line of smoke at WOT. I then run some laps hard and i'll check the temp just to be safe. Depending on the day and where you're running it can vary. My temps generally float around 220....but I've been as high as 240-250 on a hot day, still saw smoke and knew I wasn't lean.

running the engine at 190 vs 230 isn't going to make a difference as far as friction....at least I sure as hell wouldn't think so. It would be really had to test that. Once the pinch is going it REALLY wouldn't have an effect. Its not an extreme so it would be very hard to ever test such a theory.

EDIT: i meant once the pinch is GONE it wouldn't have an effect.