Seems like the same issue F-100 had. (I have touched the FM for myself >.>)
It limits elevator effectivness with speed. Solution was:
1) set the elevator effectivness in FM close to 1 (it's flying elevator, it does not have fit parts)
2) set the treshold to double
3) ever thought about the center of gravity? Modded jets tend to be overly stable which creates for some fun behavior...
No, it's total different
F-100 have a code that reduce lift at high speed, as all other planes, to avoid arcade 20G turns at mach 1.
Here the AV-8 don't want to turn from low speed
Not really, F-100's method affected elevator. Allowing 3G turns max. The max G's are limited by stalling...
LOL, i don't know what mods you have installed, but in my game F-100 turns fine, also 7,5/8G with half fuel
No idea what caused it, but with original FM, I could only reach reasonable turns at around 600 km/h - and even that was not 8G's, standard was 3 to 4. Now that I gave it all-flying elevator (the efficiency goes from circa 0.4 to 0.96 in my case), the treshold to 0.8 - and suddenly it turns normally.
No idea if it was caused by a mod conflict or I had an outdated version - but now it behaves believably. Still need to touch the balance.
Also, this:
"AI now takeoff without problems with all loadouts, human need only to increase trim pitch, don't need to touch stick"
These jets are known for having to pitch up the nose very high on takeoff, well before lift off. I think balancing itself will do. I can present my take on the FM (only balance and elevator efficiency changed, rest is unchanged - so all actual turning properties are correct.