I use Vivaldi as well but every time I update it I need to change one of it’s internal JS files to remove one UI restriction that annoys me: I use two vertical tab bars, one for showing all the tab groups and another for showing the tabs inside the selected group. For some reason Vivaldi limits the width of the two sidebar (combined) to 330px, which is too small for my tastes.

Vivaldi is very functional. But once I understood the wide landscape features of floorp, incl workspaces and all, I was sold to Floorp.