> is the way INS communicate to AP the same as FSNavigator does with its flightplan?
Good question. And the answer is: "I don't know"

It all depends if the panel developer integrated CIVA into the gauges (using the CIVA SDK) or if CIVA is just added and there is no "link" between CIVA and the gauges.
In the first case (integrated CIVA) you will have to match the exact CIVA version they used, in the second case it should work with any CIVA version.
I think that if they have integrated CIVA into their gauge then very probably the NavMode gauge would not be required (as they supply an equivalent one), so try searching in panel.cfg for "INS!NavModeTriple", if you can't find it then CIVA has been, almost for sure, "integrated". In such case, if you have a mailbox capable of accepting few megabytes I can send you all major releases so that you can try to find the exact one. Let me know (ASAP as I'm going on holiday the 28th..otherwise you'll have to wait till the 7th of jan09).
Thanks and Merry Christmas and happy 2009 to you as well!
Kind regards
Marco