PFs can perhaps be made affordable, in terms of prestige, in the economy.gf file.
[Cost/Ship/ClassType]
SHUTTLE = 1.0
PF = 1.0 // change to 0.5 to cut cost in half
...
So a 100 bpv PF can cost 100 prestige instead of 500 prestige. Unless PFs are treated exactly as fighters in spacedock. I don't see a PF item in spacedock.
Oops. I had forgotten about that Economy setting temporarily. I'll fiddle with that and see how it works.
Hopefully, that should settle one of the remaining problems with fighters / PFs, as the BPVs have to be set artificially high to obtain the correct icons in the shuttle bay UI.
Thanks again for all your help. I'll get this beast working yet!