Thanks for the questions:

Yeah the reason those hands weren't included is because they occur so rarely (they'd so up as 0.0% on a chart). You need 4 cards to make these hands and those sets are already rare for CO and BTN.

Good catch with the last point. I think I overapplied a concept I studied deeply in HU short stack. In a HU pot say at 40-50bb, We'll build our range as I described. The objective in those spots is to build polarity from symmetrical ranges and we do this by leading really strong multi component hands. In 3 way pots, we're seeing the opposite. My guess as to why that is happening is a combination of a few factors:

We may be generating too much fold equity when we hold so many components in one hand and then bet into two players (shrinking each individual player's MDF)

We may actually want villain to have hands with SDs. Since villain's are defending tighter than in a HU pot, the GII ranges are much tighter. In a HU pot, we'd hope to dominate their two pair hands, but now they won't stack off bare two pair often so we need to allow them to have two pair+SD in order to be able to stack them.

Some of these things are hard to prove and break apart in the solver, but these are just my thoughts off the cuff.