Those machines can go from idle into S2RAM just fine w/o touching the
/sys/power/state S2RAM mechanism.
It's just a deeper "C" state, really.
The confusion is that S3 is considered to be a complete different
mechanism - which is true for PC style x86 - but not relevant for
hardware which is sane from the PM point of view.
Now some people think, that suspend blockers are a cure for the
existing x86/ACPI/BIOS mess, which cannot go to S3 from idle, but
that's simply not feasible.