It would seem to benefit operators on the face of it, practically, it would be, based on your example, extremely dangerous.
An interesting example would be to compare the pilots who undertake repetitve lifting week after week, logging for example. When youre' busy and concentrating in cycles as they do, it can be quite manageable. When however, you are in deep REM at 3am, and five minutes later climbing out into the muck to LSALT, well, different situation.
My experience of it is the same as everyone, zzzzzzz, then heart attack when the phone goes, still sleeping as your strapping in so to speak.
As I understand, you have an input in to the proposed rule change, and all the concerns you have may be addressed that way.
With all things in EMS, you have the choice, don't go, if you are physically exhausted, the Captain has that discretion, the operator may not like it, but they will soon find any cut to staffing levels will end up with job knockbacks.
1st year interns experience the same type of extreme fatigue in their rediculous 48 hour shifts, they don't change it because the people who make the rules say "thats what I had to do".
Perhaps the consultant has never flown single pilot IFR, I suspect that may be the case, I also suspect that operators would not like to see their pilots sleeping during daylight hours when they could be working on administrative problems........