The Radxa Zero is affordable, as powerful as the Raspberri P4, but draws less power than the Raspberry Pi zero W2, and is a great basis of a fast mobile Linux PC which is fast and very small.
There are already instructions available for a Debian Radxa Zero mobile PC:
and Radxa Zero Debian SSD boot:
It would be highly desirable to have an updated instruction with a Radxa Zero mobile Linux PC with SSD boot, based on the mentioned instructions with Debian, or eventually ported to Armbian.