Side note: Vivaldi is excellent
As a technical user who may have a dozen windows open to extremely similar-looking interfaces (even Dev and Prod for the same customer), Vivaldi's flexibility, customisabiity and profile management is peerlessly wonderful. I can use a specific, tailored icon to open a specific profile to a specific page, giving me a window with a specific logo/colour in its title bar, so that I know exactly what to open and where I am at any time, in any window. It allows me to zoom a specific, solitary page, without causing the whole site/domain to follow. Best of all, it doesn't spy on me, giving me the best features of the Chrome engine without toxic Google spyware.
It has a longstanding problem: it crashes my machine at least once a day, though rarely twice (I suspect memory management issues related to caching)—and I still use it. That's how good Vivaldi is.