<< How, though, do I get the Dorian Minor scales to play? The Dorian Minor scale on F wound be F/G/Ab/Bb/C/D/Eb/F; on Eb would be Eb/F/Gb/Ab/B/C/Db/Eb; and on D would be D/E/F/G/A/B/C/D.>>

I think you have two options to create a nice modal backing in BIAB:
a) Enter variants of the basic modal chord, eg for Dm: use Dm7, Dm9, Dm6, Dm11,

b) Enter chords from the harmonised major scale (Cmaj in this case): eg Dm7, Em7, Fmaj7, Em7, Dm7, Cmaj7, Bm7b5 etc. If the moving bass is too disruptive, try using slash chords eg Bm7b5/D, Fmaj7/D etc.

If you listen to Impressions, for example, on www.realjazztracks.com you'll hear both of these methods for making modal backings more interesting (using all-Real Tracks)

Best - Andy