It seems that Ron Moulton, along with a lot of other British fliers, didn't understand the principle of the Uniflo tank for quite a long time. I didn't learn of it (the 'Mariotte bottle' principle, as physicists call it) until about 1967, when I was having continual trouble with my diesel-powered aerobatic models going lean as the tank emptied. I modified one of my tanks with a new filler pipe that ran straight across to the wedge (at the front, not angled back), and arranged to plug the overflow vent for flight. The resulting engine run was a complete transformation, and all my subsequent tanks have been Uniflo: the early ones were Palmer-style, with a baffle, but I found them fiddly to construct and noticed no difference between them and the simpler versions. I did once try flying with the overflow vent left open, just to prove to myself that it had to be plugged, and the flight (incredibly rich to start with, leaning-out progressively as the tank emptied) left me in no doubt.
I think Bob Palmer may have believed his 4-2-4 stroke 'switching' run had something to do with variation in fuel delivery during the manoeuvres, and perhaps he reckoned the baffle, and the positioning of the fuel pick-up, was beneficial in some way.
By the way, Ron Moulton knew of, and some people used, the 'chicken hopper' principle from as early as the 1950s, to give a constant mixture strength in team racers. 'Chicken hopper' and 'Uniflo' tanks are, of course, based on exactly the same general principle.