It's actually different, I keep forgetting to go back and do the math on it.
Technical Content Warning - Proceed only if you're into that sort of thing
The 90Hz -6dB/octave filter is a passive RC (resistor-capacitor) filter, but the way I'm doing this on More is by changing the cathode bypass capacitor, which affects the frequency response of the tube gainstage itself. This is how I did the Bass Boost in Black Eye II and the Deep switch on JC Emerald, I'm just doing it backwards on More, taking away low end instead of adding it. I did some math during the design, but I didn't take into account the fact that More has parallel gainstages, which affects the frequency response and the math isn't as straightforward as it is for a single gainstage. The filter value I chose based on my calculation was subtle to the point of being inaudible, so I tuned it by ear until I was happy with the effect.
Because of this I'm thinking about calling it a "bass cut" instead of an HPF. They obviously mean the same thing, but if you say HPF people expect you to know the cutoff frequency and slope, but if you just say bass cut nobody seems to care about the numbers