Does Tabble write Keywords to PDF files? or can it be added as a feature? This would make it very useful for searching outside of Tabble (For eg. Windows search)
PS, versioning by Last Update time is very brittle since lots of actions can update the timestamp on a file. Some options to consider – Use Created Time instead of Last update time, add the created date to the file name, use a generic sequence number – Like camera’s add to photo’s, or ideally – use an actual version control system like Git, or Subversion.