First off, I love canned starter. Dirt simple and quick. Sanitize a jug, the top of the can, your yeast packet. Dump contents of can into jug. Fill can with water, dump into jug. Shake, add yeast, done. I do this all the time with liquid yeast.
Dry yeast, though, folks say not to do a starter with. Something to do with the fact that its designed to direct pitch, and a starter hurts its reserves. It's easy enough to just do 2 packets of dry.
Maybe a middle ground could be to rehydrate the dry before adding to the starter. I personally don't do dry yeast, so definitely wait for other opinions on this.