Alright after some more clever testing I got my answer. Posting here in case others need to figure this out. I put an overdrive in front of the Maleficent Mids and tested the switch in the two positions. The overdrive makes it a lot more obvious which frequency is being boosted/cut and what the Q is. The up position is the narrow Q filter, more nasal and almost like a cocked wah in some settings (the resonance is not as pronounced as in a wah though). The down position is more slack and broad, as expected.
Cutting mids can lead to some mid-scooped metal tone with a distortion in front. Pushing mids brings you in TS and even Klon territory (without the clean blend of course). With a clean sound, the pedal can “fix” a Strat sound, giving it more mid bite (less “hollow” sounding if that makes any sense).
Anyways, working on graphics now, will post a build report next year.