Thanks you as well for the support and for the nice review.
I don't think that Firefox will ever integrate it :D. Yes it might be useful for a lot of people but that's why addons exist, and of course, it's actually better like this, in a way... Because I can expand and update the addon with many new features without being limited by some specific rules or direction. I have a lot of ideas (I would say good ones) and also lot's of requests that I look forward to implement. Of course, I will try my best to offer more options but at the same time keep the UI and UX as clean as possible. You can take a look over here and in case you have any recommendation I can definitely say that I take into consideration community feedback new features.
https://github.com/ReDEnergy/SessionSync/issues