Since mountain flying is my passion and being a MI and MOU FE I started a DTO for the MOU rating. We mainly operate out of Bolzano with a Husky. Part FCL describes how what the requirements are for the MOU rating to be maintained, but it looks as if the license can not be endorsed by hand to validate the rating for another period.
Well, I can understand your point of view. But PC12 is not my cup of tea ... too expensive for me. Mooney is fine but probably not really suitable for such utilization as a standard.
For me Piper Cub, Super Cub, Rebel are more close to my understanding. Ultralight is new, modern, popular term due to legal reasons / Piper Cub is simply proven aircraft - and Slepcev Storch is quite close to it. Low energy device - that's correct term. But energy management is essential in this case as well. Sometimes even more then one can expect. Sort of refinement of skills. The same as tail-dragger operations. :)