View Image feature
One of the few things that keeps me stuck with Firefox/Palemoon is the "View Image" feature, where you can right click on an image and choose it, and it will open the image in the same tab centered and with a dark background. If you could make that change I would be able to switch to Vivaldi full time. Another thing that would be nice is having a bookmark menu near the search bar that maintains your theme colors, or uses dark colors. Both make browsing more comfy, especially during night browsing. I think these two changes, especially the first one, would make Vivaldi the perfect browser.
That is planned and will come.
@Gwen-Dragon Still waiting.
This is definitely one of the features that I'm missing from Firefox.