I guess my main concern is using a cultured strain. Since I don't really have a good way of knowing the attenuation, flocculation, or alcohol tolerance characters of the cultured yeast.
I've had no problems using a starter with cultured strains on batches around 1.050, and have actually gotten some really vigorous fermentation this way. I've never carried over the cake to try a bigger brew with a cultured strain though. Will simply using that large of a starter make it a pretty safe bet, or am I taking a risk without knowing more about the strain?