I'm not comfortable with a typical Android screen size either, but I have a Samsung tablet with physical keyboard flip case (Galaxy Tab S6).

These two together provide a functional and workable environment for me. I haven't tried the DeX-station, but I believe that too could be quite workable with a phone.

Termux has some "soft keys" for ESC, ctrl, alt etc (user-definable). Swipe in from left, hold the button labeled "keyboard".

Hacker's Keyboard (app) is the recommended onscreen keyboard (has ESC etc).

But really need a bluetooth keyboard e.g. logitech K480 or fullsize logitech K375s - or regular USB one if your phone has OTG. Bonus: doubles screen space.

Yeah, Hacker's Keyboard makes a big difference, but I still only hit the right key 90% of the time, because I can't feel the keys with my fingers, and I can only hit a couple of keys per second. There's a big difference between making a typo once every 40 characters and making a typo once every 10 characters, especially in a vi command!

And then, while correcting it, make another vi typo, etc... a sort of event horizon, esp when tired.

Physical keyboard! With a full size one, it really feels like a unix terminal. Which it is. And very fast by 70's unix standards.

But very slow by 70s PC standards :) (Except my PC had a 9600 baud connection internally between the computer and the terminal! It still had keyboard echo in under 20ms, though.)