So, I got this idea, make it possible for planes which dont get any tracers (Top tier sweden) get them in a way that wont change the gameplay. Make those shells do no damage, or make them available only in test flight/custom missions (where mission creators could disable it).
Would make it a lot easier to learn how do guns on those planes work, its okay if you transition to stealth belts on guns you already know how they behave. After a bit of practice you see the way the shells will hit inside your head, and you dont need to actually see those tracers. I think some people will be motivated to spend some time to learn.