<<< (1) " I could easily find myself in a position where I am spending more time on BIAB than on learning the harmonica." >>>

<<< (2) "all I want is some fairly simple backing tracks to accompany myself with." >>>

1. While that is certainly true, it's not the complete answer. First, it is only true for the short haul. Assuming all you want to accomplish is to create simple backing tracks, regardless of your current skill level, musical knowledge or any other hindrance other than a physical disability, you should understand the concepts and mechanics of creating a backing track in about 5 minutes and be completely proficient within a day by spending that first day concentrating on Biab input and export skills. Second, you will likely find yourself also spending more time with any addition to your performing repertoire as you progress and expand with music. Learning your way around any professional DAW, learning to program and integrate a vocal harmonizer, or even adding a mixer will require you to temporarily stop harmonica practice and learn how to navigate, program and integrate into the new gear regardless if it's to perform publically or to practice at home.

2. I can't think of anything about the programming of a song in Biab that you should not understand the mechanics of in 5-10 minutes. If you don't know the chords to input into your project, don't know what a I-IV-V progression is or in what's the proper Key your project should be, your issue is not with the mechanics of Biab programming.

Of course there are more advanced features in Biab but they are beyond the scope of the stated goal you've set to program some fairly simple backing tracks to accompany yourself.

BIAB Ultra Pak+ 2024:RB 2024, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.