I think this discussion has lost its way somewhere and we are now just going around in circles.
Just to add a little more to the discussion,it is not inconceivable for two authorities to approve the RFM of the same type differently.
Case in point, I believe that in EASA land it is okay to hover an EC135 on one engine.It comes with a proviso that all appropriate WAT calculations have been done,and , it is an unusual operation.The FAA forbids that completely. Many a US pilot has run into trouble for having missed the little black triangle on that page. The little black triangle basically means "Not approved for US Registered aircraft".
Similarly, there is a new Revision (11 ,I think) that has been approved for the EC130.Has not yet made the cut with the FAA. Significant changes are incorporated in the new Revision ,particularly for cold weather operations, but it hasn't been approved for the line yet.I guess ( and I hope) that the FAA Rotorcraft Directorate goes into each RFM and revision with a fine tooth comb just to make sure that the operators of the type in question are not unusually burdened by onerous procedures which are necessary in other countries but not so in the US.
Final word, approving a type for a single pilot operation from one seat only means that the aircraft will not be flown from the other seat for lateral CG considerations.Does not imply that the aircraft will not (or shall not) be left unattended.
Just my 2C.
Alt 3.