My comments will certainly defer to more knowledge and I in no way want to damper enthusiasm to make one work but I've investigated using a 4 stroke trimmer conversion and getting the impression that 4 stroke conversions limit model choices slightly more than 2 stroke trimmer conversions. Some are saying the greater potential are WWI scale where a lot of nose weight will be added otherwise on low wing loaded air frames.

I really like the sound of 4 strokes. Perhaps as they become more plentiful, we will see instances where they are made to work