Hi Pat,
You are right - it is scaled according to pixels per metre.
We will release a very nice solution for the AT5 tool very soon. In the first instance, a background raster with no contours, and smooth edges, with shapefile export of contours and shorelines/islands. The shapefiles will have the required attributes for AT5 generation. In the future we hope to build on this, but even this relatively simple solution creates Lowrance maps that are far nicer than the existing LCM solution, which much better compatibility and performance.
This should be available within two weeks.
cheers,
Matt