Hi, i cannot answer the question but wonder about an aspect of your report:
Mark Fletcher wrote: > After figuring out how to disable secure boot and turn on support for legacy > boot modes, I was able to get the USB stick to boot into a non-DE Linux live > environment. The Debian ISOs for i386 and amd64 are supposed to boot via EFI. But not with secure boot, if the wiki is still correct https://wiki.debian.org/UEFI#UEFI_Secure_Boot > But the Debian > live .ISO file is MBR, and I want to install UEFI. Which URL exactly did you download ? How did you put it onto the USB stick ? Have a nice day :) Thomas