And despite their broadly similar performance, the RK3588s have significantly better power draw.
However I’m not sure of any of the rk3588 vendors that support both UEFI and have a full-size PCIe slot like the MS-R1 has.
https://github.com/edk2-porting/edk2-rk3588
https://github.com/edk2-porting/edk2-rk3588