If you use F to switch between single-shot and full auto etc then the sound made by it can be heard by other players without directionality for a very long distance, hundreds of metres at least.

This is very similar to the long standing issue of reloads being heard without directionality for hundreds of metres. It is very annoying as switching your fire mode gives your position away, when in reality it is something that shouldn't be heard beyond a couple of metres.