The OP wasn't asking for killing of friendlies to be enabled- he just wanted the bullets he fires that accidentally hit a friendly to go nowhere, specifically not into his own plane and taking off his own wing.
However, having friendly tracers fly through you would cause SA problems as you wouldn't know friendly from enemy from the tracers alone, so it would still be disrupting. Back when the field manned ack did not show tracers, I used to fire at friendlies for practice. After they added tracers to the manned ack I stopped that practice as it would annoy the targets.
