It could be argued there appears to be one rule for a two pilot operation and another for a single pilot operation.
No arguments there, there actually are different rules. In the UK a multi-pilot IR is not valid for Single Pilot Aircraft.
Calls such as "Speed, Altitude, Sink Rate, Tracking etc come to mind.
The pilot monitoring is (should) be being assessed on their monitoring, if the airline SOP has a speed call due to deviation then they should make the speed call and so on.
And... most SOP deviation limits are about the same or more relaxed than IR test limits. So the examiner should already have a very good idea of the PF's ability before the deviation calls are made.
Fly the sim like you fly the real aircraft, act as you really would and don't spend a fortune teaching folk how to work as a crew and then not test them as a crew.