I like a bit of comfort in me old age, so the P setting is fine 90% of the time.
PLUS - I may be completely wrong here, but I reckon that these EDC dampers are delicate enough without running around with them in the hardest setting all the time.
PLUS - the stiffer the suspension, the more loads are transferred to the shell, so the more stuff starts to rattle etc.
Just call me "Mr Mechanical Sympathy" !!!!