Pity to give up!
The blocking airflow over the wing issue does rather depend on the relative sizes of the canards to the rear wing and the planes general layout.
In say an XB70 the canards are relatively small and a long way ahead of the big delta but on mine they are pretty effective.
Please tell me how you made your round fuselage!!!chas
It was seriously lacking in elevator authority when first flown without them but the sheer distance between the elevons and canards does mean they have to have their own servos!