I suppose everything has been said about engine requirements but I agree with Cairoman as I see that the future would be in miniature turbofan development. Kero starting is also an interesting feature that one should not overlook too.
A question that I would like to raise at this point for discusssion is whether the present ECU technology is that good that we cannot make any further improvment to the overall current state of ECUs that are available. Perhaps a dual system which the flyer could override in an interference situation. Could be an RX issue but I suppose the ECu could also be an RX and ECU complete unit which could have a dual on-board system.

My 2 cents. Happy holidays.

Reuben