The installation instructions are still wrong. Following them will result in a corrupted device.
Composing an accurate guide is complicated by:
- android 11 and android 12 roms available on the download page
- different techniques required to flash recovery on android 11 compared to android 12
As I said above, different steps required to flash a recovery on android 12. LineageOS guide can be followed for this. (Links also above.)
No idea how you are going to present the guides now. I guess it should either be a separate set of instructions for 11 and 12 or a combined guide where two different methods of installing a recovery are described.
In my trials for flashing a recovery the Lineage way (flash dtbo, vendor_boot, then boot with the recovery.img) I used the Lineage recovery.
The separate upgrade instructions would seem to be irrelevant since if one needs install stock 12 then you need to do a clean install of eOS 12.
lemonade/lemonadep