Bob -the idle vibration on the gassers is being addressed - my Rotos are smoother than most glow two strokes - not to mention the evil 4 BANGERS.
(that was a bit nasty )
anyway - the ignition curves are being retailored thanks to addressable chips in the new ignitions .
also -my ROTO ignition saves and reads out rpm from flight - (terrific tuning tool!)
all at the cost of less than half that of the perfect pattern engines ---( under $400)
We didn't give up on the 40 concept --- just re aimed our approach -
new plane is a "bit" different
here is a profile view
you may scoff but it has extremely good response and control even at very low speeds
like hovers etc...