I'm calling this a bug because otherwise it is creating situations where players are being forced to reroll just to get rid of absolutely useless stats. For example Simulor mod with puncture?  Thus far we cannot place IPS damage on pure elemental weapons, so this creates a mod where a stat isn't just "bad" but completely worthless.  I've also heard about Critical Chance/Damage appearing on Panthera, a weapon with literally no crit chance possible.   Stats like these should fo