Where is the bug tracker?
If you think such feature of a open bugtracker is useful and missing, please make a request.
How to make a feature request for Vivaldi
If you think your problem can be solved by a missing feature, please add a request at https://forum.vivaldi.net/category/113/feature-requests in the corresponding thread for your browser version.
Ah, nice. Such request was done by @LadyJane now!