The only times I ever down shift to first are when I spin. It doesn't happen often, but some times the signals get crossed between my hands and my eyes.
When I ran in FSP (3 seasons) I never went up to third or down to first. Either you just hit the limiter a few times and then your slowing for a turn or you just mash the gas and wait for the power to come on and use that time to look ahead and set up for the next sequence. Trying to put a down shift in there is distracting to most people and by the time they figure out where their hands are, which way the wheel is turned and what their feet are doing its already too late.
Granted with some practice you can get accustomed to doing it. But if you watch some of the best drivers in stock classes they get to second and stay there. I've watched multi-time, multi-class national champs run through off-set gate sequences banging the limiter in second and be several seconds faster then the next fastest car. Gear changes can drastically change the balance of the car if not done at the right time.
It also depends on the car too. Some rev limiters are nice and "gentle" and the engine will just happily hang there and spin and spin. Others are rather "violent" and it feels like the car has hit a wall and you expect it to fall apart.
Tri-State Sports Car Council/Chicago Region SCCA/Milwaukee Region SCCA
Do better every run.
2002 ZX3 (daily)
1990 CRX Si STS (project)
2007 Pontiac Solstice Club Sport ZOK (autox)