Quote:
the rolling belt under the plane would still have little or no effect.

Exactly. The friction from the belt, acting on the plane, is independent of the belt's speed (classically; in reality it probably varies slightly, but not enough to affect this particular experiment). Once the thrust from the plane's engines exceeds that friction, the plane will move forwards, and take off, unless the belt's speed is sufficient to burn out or destroy the plane's landing gear.

That speed is probably not all that big (200mph?), and it seems technically feasible to make a conveyor belt that fast. If, as in the original statement of the question, the conveyor belt is specifically designed to carry on increasing its speed to try and match the plane's wheels, which it can't do other than by destroying them, then perhaps it is designed to destroy the wheels.

On the other hand, a conveyor belt the size of a runway moving at 200mph will cause a substantial draught of air all by itself. Depending on the exact flow this generates, it will either help the plane take off (by acting as a headwind) or hinder it (by moving air more quickly under the wings only, that the plane's motion can move air over the wings).

Peter