At about 220 lbs. system weight, I previously ran 25 mm Continental GP 5000 mounted on wheels with a 19 mm internal width at 85 PSI [F] and 90 PSI [R]. This was probably slightly high.
A month ago, I upgraded to new wheels with a 21 mm internal width and kept the same tires, but initially at the same inflation pressures, purely out of habit.
A couple of rides ago, I lowered the inflation pressures to 80 PSI [F] and 85 PSI [R]. The rear end felt slightly too soft on acceleration but handling noticeably improved, especially on fast descents.
On my last ride, I further lowered the inflation pressures to 75 PSI [F] and 80 PSI [R]. Felt about the same.