I just found a great way to use one of Vivaldi's capabilities that's been part of it for a long time, but one I'd pretty much ignored until now. That's its ability to scale the screen's contents with a convenient slider control in its status bar.
Today I was typing a message into the forum, and lamenting how many times I've needed to edit a posted message in order to fix typos I've committed. I've been a good touch-typist for many decades (even written several books), but mly laptop screen is 1920x1080, so text like this is small enough for me to miss an omitted letter or notice a double-strike.
Most browsers allow text to be scaled, but ones I've used in the past don't make that quick and easy to do. With Vivaldi, it took me a single mouse click to enlarge this message to where it's easily read, and when I'm ready to post it, just one more click on the Reset link will take everything back to normal.
As I mentioned above, this capability has been part of Vivaldi for as long as I've used it, but I'd never thought of using it in this context before. As I type this message, and quickly review what I've written, I'm very confident that no one will discover any typos in it - and without noticing that it's been edited.
Give it try, and you'll quickly see what I mean.