does the amount of sugar, the size of cereal bits, and the type of
milk have anything to do with how fast cereal gets soggy?

I haven't read the article, but I suggest you to find a copy of the
November 1994 issue of Powder Technology on pages 189-196 in which
three scientists carried a study out at length to discover the secret
behind soggy cereal. The title of the article? "A Study of the Effects
of Water Content on the Compaction Behaviour of Breakfast Cereal
Flakes" So kooky was their research that they won the 1995 IgNobel
prize for Physics. The IgNobel prize is a prize offered to crazy
science that "cannot or should not be reproduced." It's offered each
year at Harvard University.

The reason why cereal gets soggy I think is a combination of all the
factors that you described. The perfect flake or shape hasn't been
found yet.

skermit-ga

I happen to like my cereal soggy. :)

tisme-ga