I did that originally, but it felt a bit overcomplicated. It also leaves you in a place where you have two ways to group datapoints by name: either defining groups on the datapoints themselves (regex/good regex, regex/bad regex), or naming each datapoint uniquely and defining the grouping of the data on the parameters. Keeping data categorisation attached to the data felt cleaner, and they're equivalent in end functionality I'm fairly sure, so I'd rather stick with that.

Also the annotation types are nicer like this too: `@DataPoints` can have any number (0+) of names, which is trivially enforced by types, but `@FromDataPoints` would take 1+ (can't have from nothing), which you can't enforce statically and would therefore need more explicit validation functionality and be harder to quickly grok.