Instead of disappearing instantly, muzzle flash smoke should have a two phase effect: a quick burst followed by slower, reactive dissipation. light motion or wind reactions adds realism without being too heavy.
also while we’re at it, adding sparks and multiple particles making up the muzzle flash itself to give it more depth wouldn’t hurt
and for performance
pool particles, fade by distance, and use the GPU for the heavy particle simulations
a bit of smoke or fog after long fights could be a nice touch
Overall to sum it up, I just feel the muzzle flashes in the game completely lack depth and feel flat and boring…