So, are all those issues why the shop manuals specify only 119 psi for the best expected expected cylinder pressure in a compression test at 250 rpm at sea level?

Presumably the specifications assume standard atmospheric pressure at sea level. 119 psi is 90.8 percent of the theoretical maximum (131 psi) an 8.9:1 compression ratio would provide at sea level.

90 LWB RS: 3 L/mt, JBaker springs, bushings, swaybars. KYB shocks tweaked, 134k mi, original owner.
97 LWB SR: SOLD Sep. 2014 131,006 mi: running boards removed, BFG 31x10.5 AT/KO tires, Air locker, AirLifts, KYB shocks, Cibie fogs, 3rd owner.