Edit a file in two different terminal windows

Question

It's nice to edit the same file from two different views. I use a vsplit for this, as described here, and it works well.

However, I'd like to have the two views open in different terminal windows, because I use a tiling window manager, and I've already got the muscle memory to switch between two open vims using the window manager's hotkeys. Also, it's easier to tell which one is focused, because I've set un-focused windows to become transparent.

I can open the same file twice, but then changes don't propagate from one process to the other until I save.

Answer 1

Interpreting the linked Question & that Answer , we can see more about what you want :

Summary:  
   A buffer is the in-memory text of a file.  
   A window is a viewport on a buffer.  
   A tab page is a collection of windows.  

In your Case , the two terminals are 2 GUI Processes (eg xterm) , running 2 Shells (eg bash) which are running 2 vi Processes.
The 2 vi Processes DO NOT SHARE the in-memory text of a file.

Hence what you want is currently not Possible.
It may become Possible if (& when) vi gets the functionality to share the in-memory text of a file , eg through some IPC or memory mapping , though that would be buggy.