It's useful, but I could use a simpler means to get the mail address - it would be nice to have copy button upon clicking the icon - 2 clicks to have the address, instead of going to "Manage all masks" wait for it to load, sign in (I have no idea why it sing off) and then get it.

Good.

I've been testing the free Firefox Relay service for a while and I've just decided to take the premium subscription.
I find it very practical and useful.
However, a function to see which sites are used for each alias would be very useful in the future.

Very nice, but wish add-on showed emails. If a website doesnt have the autofill with relay, its irritating to click multiple buttons to get to my emails, instead of the add-on in the tab bar just showing my emails