Working with readers that are either single merged feature types or datasets that do not expose attributes, e.g. CAD, XML, JSON or OSM PBF, as an author, I’d like to have as an option to be able to see attributes that are imported in the AttributeExposer to show the number of features that have values..
Adding an option to show null, missing and empty values would be a nice feature too. When I import from cache, it would be nice to see the attribute value stats when Importing attributes. There’s room for columns to show the count for all.
With this feature, the author can pick attributes that have values, keeping the destination cleaner.

AI Assist recommends a Tester transformer plus counter to do this.
The community hub transformer AttributeValueCounter was a good option to use for this but it does not work in FME ENGINE 2025.0.x.
Just some random ideas, when Feature Cache is enabled for a workspace, during a translation run a background process can calculate the stats on the source feature types initially. Perhaps add that to the reading of the schema when a reader is configured to be added to the canvas.Get the unexposed attribute stats immediately optionally. Maybe just have a checkbox on the Import from Feature Cache or Import from Dataset dialog to allow the option.