I am not sure if this is a glitch or someone trying to hack, but in some games last night I encountered some classes (think it was the same person, didn't pay too close attention to the name) that had 3 bronze endorsements. No gold or silver was shown, only 3 bronze. All of the same type too. Seen this before?
That happens when you create a custom class but don't pick your endorsements. You end up with three times the same bronze endorsement. Most likely a bug. EDIT: replicated bug and posted a picture.
Also sometimes when I get killed by heaters on top of spawn doors, it says it was a tank with 3 bronze rate of fire.
I tried it out, and it would seem all you get is the effect of one bronze rate of fire endorsement, no stacking.
Cool! Thanks for that. Guess the person in question had indeed unlocked a custom class and hadn't filled it out. Hope one of the Uber guys takes notice.