Dave, FWIW, I'm not worried at all about adding extra components if reliability is more robust. The Xiao is already nano compenentry in size and weight.

On gasser carbs: They look fine to me and the few engines I have tested with CH ipIgnitions full gas conversions run really well, both on the ground and in the air. Not sure what MMM is doing across the pond but it's not rocket science to get a gas conversion to run good.