I find it fairly easy to make the Nav VI follow a prescribed route... using shaping points in BC.
Right. I use them when the track and the route don't match.
For example, in Google Maps/My Maps, when I draw my route, Google will always take the shortest route. Sometimes that's OK but more often than not, it isn't and I have to drag the route to where I want it to be.
When I import the finished KML to BaseCamp, it shows as a track and it will be true to what I wanted. But that track is useless when made into a route, so I have to use the route creation tool to add the waypoints in the order I want and BC will then make a route. However, BC is like Google and it will make the route look how it wants.
To help quickly find the differences between the two, I usually make the track magenta and the route cyan or light green. Where the two diverge, I drag those parts of the route to match the track and those create shaping points.
When everything is good to go, it's time to export to the Garmin. Once in the nav, the system will follow the route, but there are times during the ride that it will try to reroute, and that's something I keep my eye on.
So while I've come to terms with having to do all of this, what I hate about BC is that it's completely worthless to actually create a route from scratch without any saved or imported waypoints.