Base Camp, Trout Fishing, Nuvi 1490 LTM

BaseCamp stores all my GeoData (geocaching, campgrounds, tracks, routes, and added POI), for a given map scale, I can compare two trout streams and get a good estimate to the size of a new stream if I compare to a known stream. I use a Nuvi 1490 on the road and a Dakota on the stream. A firmware update gave the nuvi the option to not recalculate routes. I use 24k topo map to find new trout streams and I tried uploading a route to a parking spot calculated on the 24K topo map and telling the Nuvi not to recalculate by going directly to view on map. I check the gpx file and BC is sending several waypoints with the route but the nuvi is recalculating using city navigator maps. City Navigator maps has the roads I want to travel but the recalculation with a different map gives me a different route.

I did not buy the nuvi 3xxx series because at the time, they would not accept routes from BC. BC is the reason I by Garmin GPS and it looks like the Montana will accept routes from BC and not change the routes. Is it too much to hope that Garmin will make a nuvi GPS that accepts routes from BC and does not change the routes? Does anyone have information on the undocumented recalculate route option added to my 1490 nuvi? Is this possibility the start of a fix for the Nuvi line?

Thanks