Maybe these simple rules help a little bit:
1. stay with Porsche recommended tire pressures for street use, they're not optimized for comfort but for best performance combined with maximum safety.
2. if you're driving a lot at higher speeds above 250 kph, go for the maximum tire pressure for a fully loaded car and add 0.1 bar to it, so you don't have to run every day to the fuel station to refill it.
3. for track use, get a second set of wheels with tires.
If you really want to use your street tires on the track, drive a few warming-up rounds and THEN lower the tire pressure by around 0.3 bar (compared to the minimum tire pressure). The reason is simple: during HEAVY track racing, the tires warm up extremely, they build up a lot of heat and the tire pressure raises to the Porsche recommended values.
WARNING: after track racing and letting the tires cool down for some time, ADJUST the tire pressure again (raise it). A lot of track drivers forget it and end up with a blown tire on the Autobahn.
AGAIN: the Porsche recommended tire pressures are the MINIMUM required pressures, DO NOT go below them!!!
Porsche is very "anal" about tire setups and pressures, don't play around with them. Unless you don't like your life.