Its PICUS in european speak.
And you can log it in a single pilot aircraft if the operation is an approved multi crew setup. This will take into account instrument fit and sop`s.
The issue with the EASA ATPL is the skill test needs to be taken in true multi crew aircraft.
Loganair in scotland operate twotters multi crew and also the fisheries operate the F406 multi crew. Your hours are logged the same as any other multicrew aircraft.