Sorry, but I'm getting even more confused about chart updates on a multi-display network. You imply that the 'master' controls chart unlocking for the entire network, but that chart updates must be accomplished at each display individually thru it's micro card reader at the back of the display [or the USB port, also at the back of the display].
But...
Now I've discovered the "Chart automatic_chart_unlock_code insertion_instructions,pdf" file entitled for the MFD8/12/BB on the software page for the TZT2. The instructions for a single display AND instruct that this process must be repeated on EACH display,
The instructions don't seem to apply to the TZT2, but reside on the TZT2 software page.
Are they applicable?