I have not tried to mod SF yet, so my comment below may be silly ^_^
Curious, can you fake an afterburner using weapon properties? I'm thinking of an fake weapon with no visual graphics (so as not to appear confusing) that will generate accelerationg (can weapons do this) and drain energy when fired (need to tweak its duration to allow long term firing/accelerating).
You can tie it to weapon bank 4 by default (I think most people use at most 2 or 3 banks anyway..) to make it simple. One foresseable problem is that weapons require a lock to fire iirc, so unless that can be altered, this idea is useless
Just a fleeting and possibly uselessthought
-Gateway103