Originally Posted by ThomasS
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Try this sequence: Cm / Eb+/C / Cm7 / F7

It doesn't always work for all styles and instruments, but with regenerate you can usually get a satisfying result. I use this trick for other chords when I want to try a different voicing, putting the root I want after the slash and the upper notes as a simpler chord the appropriate interval above. So for example 1) CMaj7 > Em/C 2) Cm7 > Eb/C, C9 > Eh/C, Cb9 > Edim/C, etc. etc. Sometimes keeping the root out of the upper notes clarifies the harmony and you don't get awkward seconds or minor seconds where they don't sound good.

Thanks Thomas for your suggestion. Very interesting.

I just tried it in a few different situations.
I started with the chord progression you gave on a blank sheet and it worked nicely.

Strangely BIAB kept playing an interesting chord progression after your last chord!
And this went on for many bars until I finally stopped it.
In the old days BIAB would just keep playing the last chord over and over.

Next I opened up the problem song that I am working on. I started by playing the song as is.
This is the warbling organ song. It played the mMaj7 chords correctly.
Then, to fix the lousy-sounding warbling organ, I disabled Auto-fix sour notes for the track.
The mMaj7 chords were now gone!

Next I put in the Augmented slash chords you suggested, in my case C+/A and Bb+/G.
But they didn't work unfortunately, even after regenerating.

And finally, I copied the C+/A bar and then one before it.
Then I closed the file and started a New song.
I pasted these two bars into the new song and it played the chords correctly!
Go figure!

So long story short, it's nice to have this option (that works sometimes)
but honestly it would be a heck of a lot nicer if BIAB played mMaj7 chords on demand, every time.

A BIAB user for more than 30 years (if you can believe it) !