@zice FastStone is pretty cool for the price, but maybe more for amateurs than professionals. Version 5.3 is still free, but it lacks video capture, and other features.
This old feature request for Graphic Tools in Screenshot Feature is tagged as WILL NOT DO. Presumably, the developers agree with me that this is not something a browser should do.
Take a screenshot, then open the file from Windows Explorer, which opens with the latest capture selected.
Edit the image in your preferred Image Editing Program.
Or, install a third-party app like Lightshot, ShareX, FastStone Capture, etc., and use that when you want to annotate a capture.
It makes little sense to devote precious development time to duplicate features of other apps. It makes sense to improve the auto-naming and cropping of captures with Vivaldi's built-in tool.