Will

I have a bash function in fuzzy_arg that I bind to Alt-a to uses fzf for interactively inserting arguments from previous commands. It's Ctrl-r for Alt-. -- I've found it super useful for essentially inserting partial commands (single arguments) from the history

I've gone the x11vnc on a dummy display route, but found the setup's too much ceremony to want to use with any consistency.

Deskdock + barrier/synergy is slightly more ergonomic -- your laptop mouse and keyboard redirect to control android when you move the mouse out of the laptops screen and onto the tablet, but both displays are showing their native OS.

It's entirely tangential (not for android, not just a screen), but arcan does some cool stuff in this space. Here's a video of "sever tunneling" https://youtu.be/jIFjzN7dk10?t=107 (fancy x11 forwarding; It looks fascinating, but I've never gotten it setup).