syzygy,
I agree with you upon the idea that coordinate are stored in NOD files that have major influence on trip plan. And finally I found out that I mixed the index within/outside node files.
But I cannot appreciate your idea that indexes would be automatically corrected to non-shifted data. They are not 2D/3D spreadsheet with reference to other files and links. The program with index facilities such as Garmin, makes use of map data as 5-7D space and even more complex.