I wonder how much times novices like me asked this...

Is it hard-coded the instance where jet troopers are able to shot in mid-air? it may be, I just wanna make sure because nobody mods a side to enable jump and shot for normal units, that was a big mistake from Pandemic indeed, but somehow I thought there would be a work around it, or maybe not.

But it would really improve FPS experience as well as overall gameplay.

I'd really like to know this as well, although I think it's not possible on the engine. Now, if you could give a unit a hovering ability in midair, maybe just a second or two, and he might be able to shoot, but I have no real idea.

I don't think you can shoot while jumping. You can shoot while flying. The jet trooper jumps before he starts flying.