we use to implement a ‘comment’ properties (string) on our objects types where user can add a ‘comment’ to track there activity relative to each object. This property has no source column in the backed dataset, it is added in Object Editor and is served with Empty/Null content untill user add a first comment.
In Workshop we can filter on object where ‘comment’ is Null or not Null.
In explorer we can’t.
It could be nice to have such feature un Explorer.
As a side note, I often find that a temptation to start simple with a “comment” property expands as the workflows become more involved. At that point I normally have a separate comment object type - this pattern matches with the Comment widget in Workshop and also makes it easy to implement other comment-related interactions and UIs.