Thank you very much for sharing this! It will be very useful to me in a very short time because I’ve got hooked on the pi and ordered the 8GB RAM model.
However, for now I have the 4 GB RAM model and would like to boot it from the SDD with the 64 bit OS.
(It didn’t work out installing with the instructions in the archlinuxarm.org website and the result was the same with your script in https://github.com/endeavouros-arm/image-install).
Should this just work? I think you haven’t referred to this situation here or on the "recommendation for SD cards" post.