Allow users to enter their own ratings
This would allow draftsim to REALLY help train for deckbuilding/etc. by (potentially) simulating their local environment, or what they expect the meta to be at a GP, etc.
I'd be happy even if it's just uploading a CSV, and doing it each time (to not have to save anything server-side, just parse the file client-side). Letting us download a CSV template would help.
Using a cookie or localstorage to store user ratings also makes sense.