I think yer looking at it all wrong. A real fighter is inherently unstable. As in the case of an A4M Skyhawk which has no auto pilot, once you got to cruise alt got level you'd trim the plane to level and unless you encountered turbulence, etc the plane would pretty much fly itself. The second you moved the stick if you wished to get her level again you had to go through the same ritual of trimming her for that condition. If you got into a dogfight you did not continioully trim the plane for every single angle you were in or where you nose was pointed. In fact most pilots trimmed a lil nose (read very small amount here) down when they went feet dry. The reason is they had to hold a lil stick and if they needed to unload it was automatic.
Nuther tidbit....there was an airline out there that flew new planes and they had a tendency to stall them on final. Reason being the pilot kept trying to trim the planes nose while it was on autopilot. Everytime he trimmed the autopilot would retrim until he fianlly ran it out of trim. When he disconnected the autopilot the nose would pitch and whomp! They fixed that and no, it was not in the US and doesn't happen anymore
Ok that's just good reading. For this game, yes you can turn off auto combit trim. And yes, you can spend the whole flight trimming and retrimming yer plane. That can be fun and you can die alot. But hey! It's a game.
On the other hand, using auto combat trim wont hurt you and give you a chance to get used to learning about flying and fighting in the arena first.
As they say, "you ain't in Kansas anymore" and these planes ain't cessna's. Suggestion. Get used to whats happening around you. Then if you feel you just gotta trim, trim, trm all the time, go for it.
BTW, since they are prop jobs and just like cessna's in that sense. If you point the nose up they do eventually run outa steam. However, if you point the nose in any direction and let go of the stick (unload) it will pretty much stay there for a while. Isn't that what you asked about?
BTW, Im lazy. I not only use auto combat trim in most planes (some not) but when I point the nose up I hit the auto pilot angle button and sleep as she zooms when I peg my speed or alt I hit auto pilot level and go back to sleep.....well maybe not
It doesn't effect how many kills you get...honest!
Also, if I see an enemy guy trim, trim, trimming Ill prolly shoot him whiles he's getting his plane in trim