Sir Haze, I found out Aeronaut has reintroduced your glider in an updated version! It can hold a larger prop and has polydihedral wings.
Also, I was given a suggestion to use an offset gearbox to allow a larger prop. If we can get the prop long enough, we can get better climbing thrust with the gearbox. I even believe I can modify the cowl to allow us to set the motor higher and not look bad. I will do some thinking and drawing on it to see. The larger prop would be better all the way around.