Trying To Fix or Find the Right Browser/Extensions Combo

So I have been trying to find a browser that really fits my wants and needs... I love a lot of feature sets of Firefox even went as far as installing a custom CSS theme to make it not look like the default and loved the look. I just have issues with it chugging a bit on certain sites, that have a lot of client side javascript to run.

So I been looking at Vivaldi, and I have gone back to it but Vivaldi has these small things I find as tiny pain points like their forced tabs and doesn't like doing PWAs which is something I enjoy being able to make (which is another downside of Firefox as well not supporting this)...

Finally I LOVE and NEED something like the Firefox Container Tabs which make it so easy for me to be signed into multiple accounts at the same time without haveing to have multiple windows open. Like I have AWS console signed into my personal and my business accounts and switching between them and such, also my CDN provider etc... so I saw there are some "paid" solutions for this on chrome... I tried a couple of the "Free" ones that I could find on the Chrome App Store and just they don't all behave or break the site...

Feedback greatly appreciated