Have you tried linuxcnc support to run on rockchip series development boards?

 For example, rk3566,rk3588, if you can generally use what display mode, the following is the rk3566 supported by the 3D graphics engine:
 Mali-G52 1-Core-2EE

 Support OpenGL ES 1.1, 2.0, and 3.2

 Support Vulkan 1.0 and 1.1

 Support OpenCL 2.0 Full Profile

 Support 1600Mpix/s fill rate when 800MHz clock frequency

 Support 38.4GLOPs when 800MHz clock frequency

There have been attempts run Linuxcnc on Rockchip platforms.
Unlike gaming raw graphics throughput isn't a great concern.

The key to a successful Linuxcnc system is tasks happening at dependable and regular intervals., which doesn't always equate to raw clock speed. The Begle Bone Black was quite capable running Machinekit (a fork of Linuxcnc that has gone very quiet) using the on board PRUs for generating the required signals. This is a board with a 1Ghz arm proc and 512MB ram. Ran very well with Debian Wheezy.

And whilst SBC are intersting in the broader computing world, best bang for buck appear to be 2nd hand ex corporate PCs. They are cheap and provide a very easy entry for most users.

Here is a rt kernel for the rk3588:
drive.google.com/drive/folders/1r76sUsfG...6fGcz?usp=drive_link

Here you can see the result:
forum.linuxcnc.org/18-computer/48079-can...cnc?start=370#312714