for the record I tested with the x16 stacks proc when working with burst and tankbuster so it was already doing over 500 damage so threshold isn't the issue
The new items arent interacting with Mirage's marks. I've been testing and maybe its intended that now you can't imbue quicksilver reload on your 3 now despite it being possible before the patch? but its definitely supposed to proc mystic burst and tank buster, but thats simply not the case atm...