Now it happened the second time that I posted with the wrong language setting. I see a little i next to the comment, but I cannot change it anymore. I also cannot see and copy the comment to post it with the correct language. Could Summit perhaps warn me that I have a not-acceptable language set? Or let me change the setting after the error occurs?
10 days

You could use netboot.xyz: https://netboot.xyz/docs/booting/uefi