[brick]

This could be turned into a really cool math problem.
I wish I had time to devote to it.

I think boils down to this: You don't gain much value by raising the turn (you're either way behind or slightly ahead), but you open a big gap for a thinking opponent to exploit. Donk isn't folding so you're not going to gain in that way. Also, your raise for value will cause you to also lose any potential bluff bets on the river.