you've got all the good ones listed honestly. the only one i'd add is probably june of 44 (who are more noise rock but they have mathy stuff), yukon, giraffes giraffes, SWEEP THE LEG JOHNNY ("going down swinging" is one of my all time favorite records) uh.. or en.wikipedia.org/wiki/Math_Rock
Since you listed sleeping people already, you've already listed who is, in my mind, the best "math rock" band, the only one who doesn't bore me to tears anymore.
Shellac rock and have song structures and time signatures occassionally. So, I don't see a problem with them being saddled as math rock. Personally, I wouldn't call Polvo math rock -- to me that's some kind of weird noise rock. Until you get to stuff like "title Track" which is the definition of math rock. If you're going down that route, listen to thinking fellers union local # 282 instead... they've got some math rock shit, some noise rock shit, some noise pop shit,probably the best "rock" band ever honestly.
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