The closest I’ve come yet is unetbootin on Linux… even that’s problematic - it’s an appimage and has be be launched e.g.: OK - I’ve tried this a bunch of times today - I’ve tried balena etcher… I’ve tried the manual steps, of make a Fat32 USB stick, mount the ISO (loop device) and copy the files from the ISO image to the Fat32 USB stick…
And of course, I’m just going to assume he won’t be okay using Linux - so Windows 10 it has to be… But of course it has Linux on it (I was using it 18-24 months ago as a Puppet Server and running a headless install of Ubuntu 18.04 server).
Missus asked me if I had a spare laptop for her brother - and I did.