I don't remember the Pulsamatic having problems with rollover, and the main reason, I guess, is that it was never overloaded. My grandmother would do a series of smaller loads, rather than attempt one big load like people commonly do. From what I remember, the Pulsamatic's capacity was smaller than that of other Frigidaires.
About the "hypersonic" waves: A 1-18 can do the same thing, as this is what I observed with mine. Just get the water up to just below one of the top large cones, and let 'er rip. You'll see spikes that'll make Robert's Control Tower proud. I think this has more to do with how the top ring of the agitator disturbs the water surface than actual sound waves.
NorfolkSouthern