"tearing off" to me means creating a new window -- I don't know any terminal which lets you down a new window (although terminal lovers wouldn't want that I imagine).
The iTerm2/tmux integration show that's you can map TUI windows on to GUI windows including splits into new GUI windows.
It's actually possible to have both the TUI representation and GUI representation connected to the same remote tmux session.
I'm not sure how to handle something like this in a terminal editor, unless the vim plugins are aware of it (but they're not, since they weren't written for it). In a non-terminal editor like nvui, the new window could be just a view into a buffer, but still running inside the one instance of vim, allowing these plugins to keep working transparently, even though now there are multiple windows.
I don't think this is something that's easily possible with terminals without rewriting all the plugins that might need to be aware of it.