I was at Super 88 in Allston again today and they do indeed have Magnolia ice cream. The containers seemed pretty new, but there were only large sizes of this brand (half gallon?). They had ube (dark purple), taro/ube (light purple), coconut, mango, ube/coconut, maybe a few others. They did not have corn and cheese.
They also have Lil' Nene brand of ice cream, which is what I was confused about two weeks ago, I think this is the one that is made in MA. This comes in ube, coconut and maybe one other flavor. The containers looked older and more worn out, but they are pint size.
I still haven't tried any of these, maybe once it gets a bit warmer I'll feel more inspired.