When equipping and removing an iron helmet with 200% attack damage the mod doesn't seem to reset the minecraft:generic.attack_damage attribute back to 1.0 so you can put the iron helmet back on and it will multiply your current generic damage again and the only way to reset it that I found is through dying.
When equipping and removing an iron helmet with 200% attack damage the mod doesn't seem to reset the minecraft:generic.attack_damage attribute back to 1.0 so you can put the iron helmet back on and it will multiply your current generic damage again and the only way to reset it that I found is through dying.
Video demonstration