Allow document auto-save to be turned off
Include a setting in Visio Online to allow the user to turn off the auto-save feature. My prefered mode would be to only save a document when I fully intend this to happen. This would allow me to freely open and close document safe in the knowledge that they would retain there original state. Under this scenario, if the auto-save setting were set to false, a Save button would become visible in the UI and the document would only be saved if this button was pressed. (The usual warnings could also be surfaced if you try and exit with the document in a changed, unsaved state).
this is VITAL ...