How should I go about tracking changes in menu data in a consistent set of accounts?

The best way to track progress at scale is to identify a target account set. We typically see clients looking to create an account set of anywhere from 150-2000 accounts, on average, for a given set of parameters. 

With this approach, you could isolate all of your [X Product] placements in a given market, create an account set in the Overproof portal, and then be able to view and track progress against that account set in the Market Analysis tool. We are happy to help you create any account sets.