What would happen if FFG were to update the rules so that Boost and Barrel Roll, arguably taxing maneuvers on the ship and pilot, assigned you a stress token?
Off the bat it'd appear a nerf to the PTL A-wing (apart from Tycho who would become uniquely skilled overnight) and the PTL TIE interceptor, neither of which desperately needed to be. The knock on effects could, however, be quite interesting.
Reactive repositioning has a significant effect on the pilot skill game: a ship that can both boost, barrel roll and take double actions (that can double reposition) is incredibly hard to keep in arc: it can go pretty much where it wants and dance out of arc. Large ship turrets with a single reposition are similarly nerfed: they need arc dodging to avoid the focus fire that is their bane. Action economy of repositioning is critical to so many of the game's favoured builds that making them red would broadly nerf all of them, even if not equally. It would similarly be a huge nerf to pilot skill itself. Engine Upgrade becomes significantly less useful on Vader and Corran and just about anything.
A nerf to pilot skill and repositioning is a buff to mid pilot skill ships and arced ships that can't reposition: the T-65 X-wing, the Firespray, the YV, the Lambda and the Kihraxz. None of these ships are popularly considered to be overly powerful, if you get my meaning.
Red Boost and Red Barrel Roll is inherently incompatible with PTL and disables double repositioning. Reactive repositioning comes at a cost: TIE interceptors and A-wings can do it freely but other ships must consider it carefully: like a red maneuver it comes at a price.
In that sense, I think turning Boost and Barrel Roll red could hypothetically increase diversity rather than reduce it. Most of the power builds either don't care about repositioning anyway (TLT) or heavily rely on it (high PS aces and fat turrets).
Furthermore, I think it could potentially shift the gameplay back towards its initial design of much heavier reliance on predicting maneuvers and shift pilot skill back to an initiative and slight informational advantage over a heavy reactive advantage. Reposition actions are still useful (they're reposition actions!) but their power at high PS is severely eclipsed. The removal of double reposition means that if a Rookie Pilot can catch a TIE interceptor dead in its sights that interceptor can't escape.
Am I saying FFG should do this? No. But it's interesting to consider the potential positive knock on effects of what at first looks like a flat nerf to most of the game.
What do you think the potential effects of making reposition red would be?