Ouch. That must've been a long time ago, the formatter appears to have first added in Firefox 44 dev edition. But. Yeah. Unfortunately we do require extensions

Ouch. That must've been a long time ago, the formatter appears to have first added in Firefox 44 dev edition. But. Yeah. Unfortunately we do require extensions sometimes. For most users they are blocked.. I do stick to well known, Firefox recommended ones, where the extension has gone through their review. Certainly extensions can be bought out, but they'd still have to submit a new version for review with their malicious code in it, which hopefully would help. But yeah, that's not 100%. Major extensions have had issues in the past, thus the Stylish/Stylus fork.