Not sure if this extension is being updated or not, but we use it in my game. One of the players now has adamantine armour which ignores criticals. When I actually rolled a critical hit, your extension still rolled the improved critical dice, it applied maximum on the damage dice but the extra dice was ignored. I was expecting it to just roll normal damage, i.e. random on the damage die not maximum. Is this how it should roll?
I hope this makes sense.