Yenn, not really any further progressed. I still like the J430 for the ease of construction and simplicity. The idea of a low wing SP4000 appealed for the engine more than the airframe, although the carrying capacity is a bonus.
I want an aircraft that can do long distances with a fair bit of gear, hence the 4 seat bias. I suspect I will end up with what I originally planned, a J430 with a jab engine.