There has been reference in a number of threads of finding overlooked things. Back in Tinderbox v5 (before the move to the new UI), there used to be minor view windows for History and Locate; both were dropped as there was little evidence of actual use (and everything has some maintenance overhead). History, which I think travelled across from Storyspace, was simply a list of recently visited notes shown in reverse chronological order. Locate was a list of all notes in $DisplayName alphabetical order. Bother made use of $Color as an additional piece of metadata.
History, seems like what we might want for some discovery work but what is a ‘visit’? Tinderbox used to track separate (main view window) ‘selection’ and (note window) ‘read’ events as $SelectionCount and $ReadCount. The post v6 UI makes the $ReadCount attribute moot, as selecting a note in the view pane also selects it in the text pane—i.e. what was the v5 text window (note older TBXs may still show the attribute). But: did I select that note accidentally, or to check what it was (or wasn’t), or did I actually ‘visit’ it with purpose? The app can’t tell—at least unless you choose to record that fact.
$Modified tracks changes to $Text (possibly $Name too?) but doesn’t reflect changes to other attributes, such as KAs. Again, the problem for the app is distinguishing deliberate editing form accidental ‘touching’ of a value. If working via action code (including OnAdd, stamps, rules, etc.) you could create a user Date-type attribute and update that whenever you change certain attributes (i.e. as chosen by you, the user).
In some views, such as Outline (and Chart, etc.) the age of last change is shown by the colouring of the note icon. In views like Maps, the note icon’s dogear is also drawn in the aged shade. Outline-type icons also show the amount of $Text in a note (map-type icons only have the dogear).
I suspect there are a number of features above that have passed people by and are worth a re-visit—either to use as is or as a basis for discussion of improvement. I think it also fair to say that when many of these features were implemented (in the early 2000s) the app was simpler as was the content of notes.