Only the Transition tab (and the previewer) can be detached (not the other tabs)
I'm using version 3c719067 (lastest version from master using flatpak)
PiTiVi 0.14 release notes says "Ability to detach all the tabs and the previewer"
In my version, only the the Transition tab can be detached.
I don't need that function myself since I own a little screen but I report it just in case