New to v5.9.0, when ticked this saves the document (or all open documents for app-level preference) every 10 minutes whilst Tinderbox remains open.
If a document has not yet been saved (e.g. a new TBX) or is read-only (e.g. Release Notes) this setting has no effect.
Note this save is not a back-up, for which there is a separate preference. The save is the same as using the File menu's 'Save', and thus overwrites the last saved version of the file.
Default: not ticked