I wonder whether there is a limit to the size of the soundboard at which the extra amplified overtones start to muddle the cords even played in the middle regis

I wonder whether there is a limit to the size of the soundboard at which the extra amplified overtones start to muddle the cords even played in the middle register and above. Big grand pianos are not particularly transportable and organs have been designed for specific buildings; why is it that larger pianos like this don't exist as a class? Lower fundamental tones generate more audible overtones; this is why the same cord played in the lower register sounds much more muddy than in the middle. Of course it could be that even with amplified higher harmonics for mid-register. At any rate, it's disappointing that the performers chosen for their audio/video demo recordings and their recording setup are so crappy. It'd be not unreasonable to suspect the level of the piano designer's expertise is comparable. And, of course, size of the soundboard alone does not a good piano make.