Awesome, great service, definitely worth more than $1 a month.
The addon breaks some forms as it's overlaying things it shouldn't or gets bigger than before, but it never completely broke a login.

EDIT:
I do not want a custom subdomain, because that would allow anyone to generate aliases.
But maybe you could generate some subdomains or even new domains that all of us can use to bypass some apps that block @mozmail.com.