Ok, I got it figured out. Problem was that it’s such a seamless experience that I didn’t notice the change.
I had taken a KML of all of a national forest roads and created the OBF for OSMAND and loaded into the root folder for OSMAND to add to the existing maps. It was blending it in with the maps already loaded so smoothly that I didn’t notice it.
I thought maybe that was happening and I tested it by naming a road something distinct and then loading that file into OSMAND. It worked and added those additional roads into my map display.
Cautionary note here though. I don’t think those roads are available for routing and navigation. They’re not connected to existing OSM road data and I don’t think the routing engine is smart enough to navigate a road not connected but nearby.
I wish I could include this Vector Map data as an overlay or underlay option instead, but it appears that over/underlay only support georeferenced raster maps.