allTurrets slammerUp returns 0 while it is expected [[0],[0,0]] since commander turret has an MG. However allTurrets [slammerUp, true] (include FFV turret) does return commander turret, I'm guessing because you can turn out and use FFV.
I hope this inconsistency will be resolved without breaking people's scripts that count commander turret with MG as an actual turret.