Can we have a "webextension" tag, (and/or a tag for E10s)?
PS: Saying "I disagree" if you disagree, is enough, no need to downvote every tag suggestion.
webextension tag would only be useful when used in conjunction with other more specific tags such as an actual product tag, as such it would be a meta tag.
Problems with programming issues for the
webextension API interface would off-topic here and be better off on Stack Overflow.
I don't see a compelling reason to create this tag at the moment.