TabFusion

It's the only tab merging extension I found which also has the option to exclude the merging of "app" tabs, which makes it the BEST!

Yes. Now my Jupyter Notebook can live as a seperate app window and ignore all invitations to join.

It accomplishes everything it claims to do with no downsides. As a dual-monitor user, having a quick access button to automatically pull tabs off a separate browser window onto another window is made hassle-free. Now I don't need to drag every tab individually off one window to another.