Thank you for your request. As this post has had less than 5 votes over 4 years it will now be archived.

I would definitely use this if it were available as a keyboard shortcut, too, and for left/right scrolling as well. Currently there are PgUp/PgDn keyboard shortcut commands available, but I'd like to use j to scroll up, k to scroll down, h to scroll left, and l to scroll right (this matches scrolling behavior from vi/vim).

Smooth Scrolling is a very important feature. I like Firefox Smooth Scrolling implementation.

@oldhickory30 Thank you, thank you, thank you! I've been having this problem for years (on Windows, so it's not only a long-term issue, it's also cross-platform!), tried uninstalling extensions, reinstalling the whole browser, playing with settings, and today I found this topic and your solution turned out to be right.
So why does the team not fix this bug after so long? Why does laptop touch-scrolling have to wait until you stop the movement to figure out you're not using gestures and start the actual scrolling? This is a huge issue - to the extent of making the whole point of using Vivaldi over Opera defunct.