Love your post it was super helpful. I have one a massive issue i couldn't fix no matter how much I've tried :
I have a PocoPhone F1 with LineageOs & Twrp. I can get into twrp but for whatever reason the touchscreen is not working, so I wanted to flash it with a newer version (to then flash a different rom).
Now the usual method for this is by using fastboot, but fastboot gives me a couple of different errors each time I try use it : "Sending 'recovery' (31068 KB) FAILED (Write to device failed (No such file or directory))" and "Too many links" are the most common ones.
Sometimes it just hangs after I type a command, no error no nothing just a blinking cursor (e.g. I type fastboot reboot and it just sits there).
I don't know if / how I could reflash the recovery. Just loading into it didn't work "fastboot boot recovery.img" "Can't write files to phone". It doesn't list partitions.
I couldn't find a "solo adb" solution since that tool still works. The phone still boots, so it's not a brick.
I'm sorry that I couldn't find a solution on my own