In Item.java the interface DoParam is dedicated to mods and allows compatibility.
As such, this problem is minor.
Nonetheless
When applying DoParam to primaryAnimMask, half of the override is missing, it should also include:
this.replacePrimaryHand.maskVariableValue = this.primaryAnimMask
When applying DoParam to secondaryAnimMask, half of the override is missing, it should also include:
this.replaceSecondHand.maskVariableValue = this.secondaryAnimMask
Regards,