Perhaps this is a strange ask.
I already have a laptop (#1) running Ubuntu 20.04LTS.
Question 1: I want to install Ubuntu onto a bootable external USB drive (flashdrive or SSD) from the existing Ubuntu environment (laptop #1) without having to boot the Ubuntu live installer flashdrive. Is this possible?
Question 2: Once I create this bootable Ubuntu external USB drive, I would like to use it to boot another (Windows 10) computer (#2) into Ubuntu. Meaning, can an bootable external USB drive created on one computer be used on the second computer? Is this possible?
(Actually, I don't want to boot the other Windows computer (#2) with the Ubuntu live installer and mess around with the other (#2) computer's Windows bootloader - as I've had some problems in the past already.)
The full log of my past problems is here: [Unsolved WIP] How to install Ubuntu on bootable external USB SSD
If all this is possible, how do I do it?