Burst Fire abilities that apply effects that can stack erroneouly multiply stacks by burst shots.

[Mitzruti]

That is, if you have a three shot burst that's supposed to apply 1 stack of an effect per hit, it will instead apply 3 stacks per hit for a total of 9 stacks.

The good news is that this should be easily fixed: just remove the totally unnecessary code that does it from OnRefresh is XCGS_Effect.