New to v5.9.0. At app-level only this preference causes Tinderbox to open the last-closed TBX document. If several TBX are open in a session, only the last TBX to be closed will re-open when Tinderbox re-opens.
This can be useful for those who only ever use a single TBX or have a primary TBX they always wish to be open.
Default: not ticked
N.B. This item is not displayed in the General tab of document-level preferences.