Feel free to try with rpi4 since we provide 64bit images for it.

I only have a Raspberry pi 4 or 3 to play with. Would that do?

32 bit Debian / OMV packages could be a problem. Can you try the same using some other hw platform?

So something is wrong. When booting up the i can see all the checks that debian normally does. But then my screen turns black and the disks spin down. I will try to see when this happens an if i can see the error on the screen.

you can probably run it directly in the shell that wsl presents, which has to be in Ubuntu itself. But that PREFER_DOCKER=no runs the build directly in that shell without spawning another docker instance. root (via sudo called internally) is needed to run it, but that it mostly stays within the build folder. root is needed due to the use of loop devices which is used to create the image. it can be run as root without much fanfare and it should complete a build and leave your image in output/images. flashing that image is the same as how you would when you downloaded it say from Armbian https://www.armbian.com/orange-pi-zero-3/ building from source opens up all the knobs and switches that you can tweak, I think it is even possible to change the kernel version. standard selections offers current and 'edge'. 'edge' is what I mostly choose as that would be a more recent kernel than stock. you may need to explicitly 'enable', rather select your board (i.e. orange pi zero 3) from the menu presented during the build