I’ve read a lot of threads regarding inner/outer / dual AR coatings. I know my seamaster has dual coatings and it really does make the crystal disappear at some viewing angles. I haven’t managed to scratch the outer coating enough to bother me but I can detect slight swirling in bright sunlight. For me so far I like having dual coating
I don’t know if I answered, just commented. But I think it’s really a visual thing, if you’re unsure if you have the coating see if you detect a bluish/purple tint on the glass in direct bright light/sunlight