"Update page" popping up is frustrating! I suggest replacing it with little banner under youtube videos
Man, this is a really bag UX to popup on every plugin update.
Imagine the user (me) right in the middle of something, like reading or even gaming, and SUDDENLY youtube extension page pops up.
I understand the issue is serious and it affect people. But I'M OKAY TO WAIT. 48 hours is not a big deal after all!
Here is my friendly suggestion: put important updates in a little banner under the video when you click "download". This would be the infromation that is needed when it's needed most: when I want to download a video youtube. Something like:
"Youtube downloader plugin is having some issues now. If you have problems downloading, visit this page: [link to the support page]"
This will make for much better UI and more happy users.
Also, I appreciate how much work you are putting into this extensions, and it's really useful.
I can understand the situation and feel sorry for that, The updates are not handled the way you think, they are pushed automatically by Mozilla.
You can disable this behaviour in future using these instructions – https://blog.mozilla.org/addons/how-to-turn-off-add-on-updates/