I'm loving Orion browser so far, but find that when it comes time to have multiple tabs side by side, it is clunky to have two separate windows for one task. This feature would allow native support to splitscreening tabs like on some other browsers (right click tab -> split view), which would place the tabs side-by-side.
If there were any workflows that needed or would benefit from having two tabs open at once, like for writing off of a source material, working on two separate documents, inputting data to spreadsheets, etc. A few other browsers have this feature (I know Comet browser does but I'm pretty sure another browser had it before them, Helium browser)