@peteos, I managed to install 2.7-U, via ADB and Fastboot.
So first flash 2.7 recovery, with flashboot flash recovery recovery-e-2.7-u-…beyond0lte.img.
Reboot in recovery then enter Advanced, Enable ADB, then arrow back, Select Apply Update, Apply from ADB.
Then adb -d sideload e-2.7-u-20250109460550-community-beyond0lte.zip.
I know this is a very short, how to, are you familiar with ADB and Fastboot?