I hope I'm not getting my terms crossed here and that I'm understanding your points clearly. I believe your post focuses on collaborative work, where users on different computers can work on a file together at the same time. By "collaborative", I mean: multiple simultaneous instances of a file loaded on different computers, where the file is being edited, and saved back to the same Dropbox storage location, within the same time frame.
I do appreciate your thoughtful and thorough response about the design of collaborative work using Dropbox. However, if I understand your post correctly, my use case is quite different in practice: one instance open of the file at any given time where the file is edited, saved to Dropbox storage location, and closed. Then, and only then (and only after Dropbox is "up to date" on both computers), may the file be opened on a separate computer with a similar use of the file.
I would like to hear from others who have had experience using Panorama X and Dropbox under these conditions. Is there anyone who has experienced issues with Panorama X file integrity or Pan X refusing to quit while using Dropbox in this manner?