I imagine that it is easier to keep a big plane in ground effect than a small one because the relative size of the boundary layer to the size of the airplane is

I imagine that it is easier to keep a big plane in ground effect than a small one because the relative size of the boundary layer to the size of the airplane is a lot larger with increasing wing area. The Soviets had several working prototypes that managed just fine while carrying heavy loads, and there's plenty of videos of glider pilots effortlessly gliding along for hundreds of metres in ground effect over runways and the like. Also no offense to rctestflight's impressive skills, but his aerotech skills seem to be mostly self-taught (he studied "applied film at business knowledge according to linkedin). There would be a huge different between what a talented amateur can achieve and what a team full of trained professionals could build. Staying in ground effect seems like an ideal job for a flight computer to manage btw, autopilots never tire and always stay focused.