I think PG-Music needs to have an over view course web page for absolute beginners on this topic "making the melody track such that it does not turn people new to BIAB off". The beginner steps through the course topics in prerequisite sequence after they get the overview. If they think they know a topic they (don't drill down into the details but instead skip to the next topic). So as an example entering melodies could be a topic with two sub topics (manual notation entry and midi instrument playing entry). When I first got BIAB in 2012 I would process that topic but now I would skip that topic.
Part of the output section of the course should be "select Midi Super Track" rather than "Select Midi Instrument". I just tried this and to my ear some of the piano super tracks sound like real pianos a student would play. If I was forced to bet I would bet real instrument.
The course could have a sort criteria such as "low budget" "high budget" or "little time" or "endless learning time". I would chose "low budget" "Little Time" at present but that could change.