How long would it take to add the expansion tile selection as an optional checkbox like raging or chill barbarians? Even if you couldn't add an automate checkbox for when the game got later, I'd still use it if it was available. (Assuming Whoward would let us use it, but from my brief interactions with him I'd guess he'd okay it if asked.)
A lot. And you know my rule: no features for humans that the AI can't optimize/get.
G