"He who marches out of step hears another drum." ~ Ken Kesey
the issue is that you not only have a cantilever system where the pressure to the squeegee is coming down from one side, but also that the squeegee can 'float' side to side. when printing in a high shear, high speed method, you really want pressure on both SIDES of the squeegee, so that the platen and shirt can't cause the squeegee to lift up on either side. remember, you're just trying to kiss the top of the shirt.I think that 'self' leveling print head designs like that are nearly as bad as a tuned up old Javelin... you have to print with so much pressure to overcome the rocking potential that now the squeegee is bent over.
I have no direct experience with the newer style machines.however, I have heard reports from people that I trust saying that they're having problems clearing one side or the other side of a screen when printing with super low pressures on some single-point presses. The only working solution in some of these cases is to just add pressure and let the squeegee deflection act as a shock.this would seem to indicate that the pressure isn't consistent side to side... which is what a dual-point chopper pneumatic driven system tries to solve.the chopper presses down with X pounds of pressure on either side of the blade keeping the interface pressure between the blade and the screen (and thus the shirt) consistent.having a system where the squeegee is free to rock back and forth means you're only pushing down with force in the middle. The force at either end can be different... the most apparent form of this would be a see-saw... the middle of the seesaw is like the pin/pivot... the ends are the ends of the squeegee... if one person pushes up, no matter how much pressure the middle has, the other end is going to go down, or vice versa.
... I can now control the squeegee pressure in the cylinders via the regulator, and I can dump the air with the switch so I can insert / remove squeegees without having to turn the air off to the whole press.