There was some discussion of this during my refit. My drive train was entirely modified by a previous owner, but various photos from the interwebz suggested that such extension beyond the strut may have been common on Ericsons. I think that 3/4 inch shaft stuck out at least four or five inches.
Since I had already bought a smaller diameter prop (Indigo prop supposedly optimized for A4 engines) that did not fit the existing (weird aftermarket) shaft, I had to buy a new shaft anyway. I compromised and made it an inch or two shorter, but kept the prop/hull clearance the same. It remains to be seen whether that was a good decision, pending close inspection on some future haul-out. As far as I can tell from a brief in-water inspection, it's doing OK.
The old shaft was significantly worn down in the area of the cutless bearing. But consider also that it operated almost entirely in river water full of glacial silt and basalt flour.
