Like the title says, it's not really something that complicated and I can't imagine it would be that hard to implement. While the cases of wanting to turn off the skin exclusive sound effects are probably slim, it could've been a miss click by the person or they might regret upgrading the gun. I get that getting the radianite points refunded every time you de-grade your skin is unlikely, but having the freedom to customize the skin the way you want it and whenever you want it would be a really nice quality of life change. Also as a side note sometimes the VFX of the gun can cost more fps for lower-end pcs, skins like the glitch pop, or elder flame collection.