The only pressure tapping points that exist on later models of the 5HP24 are for the B & E clutches and the torque converter.
Very early transmissions had pressure tapping points for just about everything. If we look at this early cut-away transmission from the official repair manual you can see pressure tapping points for PH, A, WKa & WKz (as well as the main flow to the cooler ZK)
Indeed, the overhaul kit still contains plugs for all these tapping points.
Over the production lifetime, the casting was modified. First the tappings were no longer machined,

PH, A, ZK, WKa & WKz

F, D & C
and then eventually the majority of them disappeared altogether.
The solenoids operate off a regulated 5 bar supply. I would guess that the main pressure typically runs around 10 bar (A clutch pressure will be the same), maybe increasing to 15 bar for Reverse?
Phil