Slowrotor, my take on this is that multiplanes deserve another chance. Monoplanes only have huge advantages in terms of parasitic drag reduction, particularly at high speed. At low speeds multiplanes come into their own, since for a given wingspan you can produce huge amounts of lift. It is no coincidence that all of the early flight attempts, with the limited engine powers available, were biplane or triplane. I have even seen footage of a conventional bicycle getting airbourne (only briefly, due to control loss)!
Why not design an ultralight that has an additional wing set or two? When established in flight the auxiliary wings could be folded back out of the airflow, but they would be pulled forwards for landing. Perhaps you could have a mechanical arrangement so that the lower aux wingset moved forwards, and the upper aux wingset moved backwards - This keeps flight symmetry, and avoids high control forces. Maybe even a drag servo on each set depending on whether you wish to deploy or stow...
Mart