I've done the plate snubber both ways, with a cap over one resistor with a second in series, and then with a cap over a single plate resistor. For me, I prefer the latter method, just one plate R with a bypass cap. Cameron is another builder I can think of that commonly used the one plate, one cap method.
I'm hypothesizing that Friedman only bypasses the 100k plate with a bare 220k plate in series to reduce the treble cutting effect for one or more reasons. Firstly, he uses a 500pf cap, which is fairly large (1000pf have been used by others). Secondly, he uses multiple snubbers in his amps, such as the V2a plate resistor, and v2b 100k cathode resistor, both also 500pf. So I'd assume he's limiting the effect of the 1st stage plate snubber due to the others also in circuit.
I use a snubber on the 1st stage plate in most of my amps. Smaller than 500pf, though. I've experimented at length in this position and it almost always sounds better with the snubber. It 'cleans up" the scattered top end and makes the amp sound more put together. I don't realize any significant degradation of the top end with the cap over a single plate resistor. It's one of the best places to put a snubber, from my experience.
There's lots of room to tweak. You can go to a large value cap, but only snub one resistor out of two in series, or you can go the other way, using a smaller pf cap with just one resistor. So your effecting frequency and the amount of effect of that frequency by adjusting these values and layout.