I've tried a couple of ways to get a USB stick to boot (bios not efi) with persistence from debian-live-11.0.0-amd64-kde+nonfree.iso. Just stuffing that to the stick produces a working stick, just no persistence.
The sparse instructions at https://wiki.debian.org/DebianLive/LiveUsbPersistence result in a stick that doesn't boot. Blinking underscore text cursor top left of the otherwise black screen. So syslinux doesn't even start. Using mkusb-minp and the instructions at https://help.ubuntu.com/community/mkusb/minp/details I end up with a black screen with a movable mouse cursor. So KDE tries to start but gets stuck somewhere. I can switch to a virtual console and kill sddm but trying to start KDE with startx ends up in the same situation again. Granted, the instructions are for Debian 10. Also, somehow mkusb-minp seems to do changes to the live system that I really don't like. Other than messing up KDE it also seems to go and mount all partitions RW and feels free to run fsck on them too. Wild for a live system and I'd really rather it didn't do that. Straight up live system doesn't do that or at least I haven't noticed (and I'm pretty sure I'd notice.) I hope this is not a common idea on how a live system with persistence should behave? A quick try with GRML and their tool grml2usb seems to work for text boot. I guess I can see what happens if I install plasma-desktop or actually task-kde-desktop on it. Anyways, any known working methods? The goal here is to try out Nvidia's proprietary drivers in Bullseye before updating. I'm sure I can do that without a DE to save some time come to think of it. My attempts to use drivers from the nvidia-driver package in a live system hasn't been successful so far, no image from the card. It might be caused by the nouveau driver loading automatically. That's why I'm trying to get persistence going, so that I can reboot with nouveau blacklisted. Hoping for answers.