Annotations are great but have significant limitations. Conceptually, the idea of being able to let users tag data that will propagate across other similar data set is a great tool in terms of synchronizing insights.
I think there are a couple improvements that would be really helpful. The first, which is a major departure from the current implementation is to expand annotations beyond just being bound to dates. Text dimensions would really benefit from annotations from a footnoting standpoint for a report.
Say we have data about vehicle collisions. In this set, there is a community where there is a bad intersection that has been determined to be a contributing factor to a large number of collisions in that region.
In this use case, there's nothing related to dates. But you may see a huge spike in accidents if you group by community in a report or chart. It would be great to be able to tag that community in the community dimension as something like "Downtown Intersection has high incident rate."
Then, whenever you run a report where that community is in the mix, it would be able to generate a footnote (preferably at the bottom of a chart or report, with a tooltip or flag within charts and reports.
Additionally for date-based reports and charts, I understand that the date must be in the report in order to show. It would be great if a report had date filters, and the date was within the range, that a footnote could be generated as well.
Hopefully others agree!