The problem here is, that at least in Germany S-Pedelecs are not allowed on bicycle paths at all. Which makes city driving a nightmare and is also preventing S-Pedelecs on many other paths. Around here there are many paths through nature reserves and woodland, where it totally makes sense that motorcycles are banned, but since S-Pedelecs fall into that category, you are screwed.

A regulation like “feel free to drive there, but do not even think about going faster than 25km/h” could work.