hi Magic Banana
I used the webpage below as my guide to install pendrivelinux
https://trisquel.info/en/wiki/how-create-liveusb
I apologize for the above long story but all the details are there.
I decided to park the original bios-settings issue for now, and focus on
getting to the Trisquel bash command line from the USB.
I don't speak French but I read your
https://trisquel.info/fr/wiki/d%C3%A9marrer-un-syst%C3%A8me-live-installable
using google translate.
From what was translated I did all that was in your guide by my attempts to
alter the BIOS (UEFI) to prioritize the USB.
I am considering some alternatives, such as using virtualbox or similar
app...