Ollie, interesting topic. I don't think I can approach your question using the criteria of tracks from post Fools Fall In Love albums because of the way music changed from the second album to the last. However, what I will do is compose an album of songs from the original Fools album along with songs done by other artists that I think Diana's take may have been interesting to hear.

Sweet Surrender
Mirror, Mirror
It's Never Too Late
Think I'm In Love
Work That Body

There Goes My Baby...done in an uptempo funky vibe
Silly...by Deniece Williams
Very Special...by Debra Laws
Out Here On My Own...from Fame
You Can't Turn Me Away...by Sylvia Striplin