While not RC, this is a fascinating design
https://www.mby.com/gear/sharrow-mx-...opeller-110120
The Loop propeller nearly eliminated cavitation, slip, and has quite a gain in efficiency.
https://www.youtube.com/watch?v=X7pJqFgzXp4&t=1s
Real world test show a bit improvement in efficiency across the entire operating range.
Bookmarks