One update I didn't make is that I'm now getting 5000 RPM out of the engine with the Byron 3-blade prop. Still lower than what I want, but now in the 5000-5600 range spec'd for the combination.

Mixture and break-in time seem to have had little impact. Biggest change came with the position adjustment of the ignition timing sensor (using full electronic CH ignition, not the throttle coupled advance setup).

Talking with CH, this change in position setting may likely have been required do to altitude differences and/or plastic creep - the kit/engine did sit unbuilt and unused in box for several years before I obtained them.