As title says, those last tracer rounds at the end of 30-round magazines are much more of an annoyance than of any real use.
In real life, I know the reason for tracers at end of mags is to indicate the shooter his gun is about to run out of ammo, but in ARMA 3, all it does is reveal your position to the enemy and put your life at risk.
With the HUD displaying the ammo count and the inventory giving a visual estimate of how much ammo is left in each mag, there is absolutely no need for those revealing tracer rounds, especially since the MXM now uses the kind of magazines containing those tracers, which puts lone marksmen at great risk unless they take the time to tediously discard every mag having reached the tracer rounds.
Even in the eventuality that clues about ammo count could be disabled at the discretion of server owners, I'd much rather run out of ammo unexpectedly than give away my position.
Please Bohemia, express common sense and remove those tracer rounds at the bottom of magazines. If I had control on every round contained in a magazine, I would actually take the time to empty all of them just to throw the bottom tracers away and refill everything with normal rounds.