Harrumph.
No dice @richard_le_,
As below (for future archeologists to study), I took 9 whacks at it and at last do indeed see what you reported, but after checking my usual API nook and cranny resources, grudgingly conclude (as you did) that the limit of 20 is As Designed. I also noted that the 20 that do come back appear to be in the same most-recent-first order as we've come to expect on the Updates tab under a project, which might further imply that This Is Just How It Works (even under api-unsupported, btw).
So! In addition to the NOTES workaround I suggested (which does seem viable), my other suggestion would be to use my Targeted Auditing technique to automatically capture such updates in a fit-for-purpose project level custom parameter, an perhaps add a dash of something similar to The Scoop to help display "aging" comments in a more visually obvious fashion (i.e. recent Red > aging Purple > old Blue).
With that, I'll file this one on my Watch list, in case someone does know of a secret syntax that's eluding us...
Regards,
Doug
// trying to pull more than 20 Notes as part of a proj request for Rich L
// step 1: find a project with lots of notes
https://atappstore.my.workfront.com/attask/api/note/report?fields=project:name&project:name_1_GroupBy=true&entryDate_AggFunc=max&&entryDate_AggFunc=min&entryDate_AggFunc=count
// step 2: look up the notes directly for that project ID
https://atappstore.my.workfront.com/attask/api/note/search?projectID=52a51c5900016f91f45550c3c33100fe&fields=projectID,taskID,noteText,auditText,noteObjCode
// step 3: ask for the notes as part of the proj call...RETURNS NULL ON ALL NOTES
https://atappstore.my.workfront.com/attask/api/proj/search?ID=52a51c5900016f91f45550c3c33100fe&fields=notes:auditText,notes:noteText,tasks:notes:auditText,tasks:notes:noteText
// step 4: count projects with non-null notes:noteText
https://atappstore.my.workfront.com/attask/api/proj/count?notes:noteText_Mod=notnull&fields=notes:auditText,notes:noteText,tasks:notes:auditText,tasks:notes:noteText
// step 5: search projects with non-null notes:noteText STILL RETURNS NULL ON ALL NOTES
https://atappstore.my.workfront.com/attask/api/proj/search?notes:noteText_Mod=notnull&fields=notes:auditText,notes:noteText,tasks:notes:auditText,tasks:notes:noteText
// step 6: try api-internal STILL RETURNS NULL ON ALL NOTES
https://atappstore.my.workfront.com/attask/api-internal/proj/search?notes:noteText_Mod=notnull&fields=notes:auditText,notes:noteText,tasks:notes:auditText,tasks:notes:noteText
// step 7: having typed in 22 updates (notes) by hand at the project level for a particular project, search for them against the NOTES object directly (using the 2024-04-05 prefix on each such note 01, 02, ... 22) WORKS
https://atappstore.my.workfront.com/attask/api/note/search?noteText=2024-04-05¬eText_Mod=cicontains&fields=projectID,noteText
// step 8: attempt to bring those NOTES back via the proj search STILL RETURNS NULL ON ALL NOTES
https://atappstore.my.workfront.com/attask/api/proj/search?ID=52a51c5900016f91f45550c3c33100fe&fields=notes:noteText
// step 9: switched to UPDATES:MESSAGE instead of NOTES:NOTETEXT and at last retrieved those updates in a collection...but (as Rich observed) see only 20 of them, in descending order. Harrumph: As Designed.
https://atappstore.my.workfront.com/attask/api/proj/search?ID=52a51c5900016f91f45550c3c33100fe&fields=updates:message