@Charles. Try this with the GPX you posted:
Create a route within OsmAnd that goes from your starting point to your destination. (Give it some time to calculate.) When I tried it, the OsmAnd-calculated route appears to follow your GPX exactly, or at least close.
Press the directions button and then the middle of the Distance/Time field
From there, you should see directions. I think those are the directions you'd hear when you actually do the route. How do they look vis-a-vis your original question?
When I tried to navigate your GPX directly, I got the expected generic directions: e.g. "Turn slightly right and go." "Turn left and go".
RE: BRouter. I thought the Web version has an auto mode--but again, I've not done much with it.