Basic strategy, by definition, is the best way to play against the CSM. With a standard game, which is not shuffled after every hand, basic strategy is the best way to play every hand on average, but isn't necessarily correct at any specific time.
That is, sometimes you should play differently than basic strategy based on the remaining deck composition. That never happens when you are playing against a continuous shuffler (with a few exceptions caused by the handful of cards visible on the table.)
So, rest assured, basic strategy is ideally suited for CSMs. That is, if you must play against these awful things.