If it doesn't affect your tone or maybe you like the tone now, all it was, or functions as, a high-cut smoothing filter - kinda' takes the high end (upper audible range) "Snaps" that may occur during switching loads - rounds off their "edge" into a curve. Much like ANL filter caps.
You'd be better off swapping that out - the Mylars are common, but not indestructible. Considering their construction - can be subject to damage from vibration, pressure/stress and they use "aluminized paper" a lot like the Electrolytics do, only without the electrolytic (no galvanic effects) - the size of it - I guess the value to be between 0.22uf (224) or 0.1uF (104) these are not polarized so they can be swapped with ceramic discs if you have spacing issues.
Regards!
:+> Andy <+: