I think Sculpt would be quite promising for hibernation with the RK3588. It already has those features on x86 despite Haiku, a much more popular alternative OS, not yet having implemented suspend.
I suspect this is because the underlying Genode uses a microkernel, and certainly so much smaller and more manageable than even Haiku. It would thus follow that Sculpt can be customised (sculpted!) much more easily to the Reform hardware than linux. Genode also majors as a hypervisor for guest OS such as linux.