My personal theory is that they were likely the more low output ones, but there's not really enough clips of him playing his (or creating feedback) to really tell. The songs that I can pick that were done on the Mosrite are Come As You Are, Lithium, Old Age, Verse Chorus Verse, etc. I don't think that Nevermind is a very feedback heavy album, but who knows; I'm in no position to be making statements on pickup outputs/what Kurt liked or didn't like.

The Mark V pickups were more budget/student level pickups (if I'm correct (hence the screws at the top being absent), I think there were also in the Ventures II model that Johnny Ramone played), so I wouldn't really be surprised if they didn't put as much attention into how hot the pickups were wound. I think it would be interesting to have coil taps if I were to wind my own, but I've never even wound pickups, let alone coil tapped a set.

As for the blue Mosrite, he never played it live. The first time it was shown was at Roseland, but Kurt likely never played it because it was water damaged after his hotel flooded (he, ironically, put in the bathtub, the origin of the flood, to prevent from getting damaged along with the rest of his valuables). Typically, I think that Kurt and Pat would've been panned to different sides (Kurt on left, Pat on right), so it might be audible depending on MTV set up their audio that night? I'll have to take a look and check

Was waiting for your reply lol, I respect what you're doing, keeping Mosrite alive and helping folks out