@Nathan_Boyer - the idea, if I understand it correctly, is to change the name of the feature we add from “metadata” to “notes”. All else would be unchanged. You still would be able to store a dictionary mapping note names to note values.
So from the functional perspective nothing would change in the PR, except for one thing - we would not automatically propagate metadata from other tables in DataFrame constructor and most likely the functionality would not implement DataAPI.jl interface (which will be obsolete), but will be DataFrames.jl specific. What would be changed is name of the feature, which would more clearly convey the purpose of the provided functionality.
Would that work for your use cases?