In my personal phone when I click on the eBay app I login once and that it, for my personal PC I need to login frequently even If I click on keep me logged in option. Banks app uses the system authentication on the phone to automatically login.
So, what I am advocating for is that Vivaldi (maybe after a warning to the users) allows the user the option to log in automatically to site I chose.
If I visit a site that requires log-in in and Vivaldi has the log-in information [Log me in automatically] whenever possible or find a way to keep the connection alive … so you’re never logout.