Vivaldi is not open source. Not quite an option.
https://vivaldi.com/source/
I think the UI code is not open source (so you can't build the browser yourself).
https://vivaldi.com/blog/technology/why-isnt-vivaldi-browser...
Wait, what? Vivaldi is open source? Now I am confused and really not sure what was the reason I ignored it for so long. Was there something iffy with Linux desktop integration?
It is not open source. Some of the backend is.
