[IMP]TAB - drag and drop to open in new window
I believe that the Title of this post is self explaining. At this moment, to move tab new window, you need to right click it - > Move TAb - > New Window.
Would be realy nice if you just drag and drop the tab to other monitor, which will automatickali open a new instance of Vivaldi.
@radko25 - This is already possible in 1.5. What version are you using?