That's very true! We are trying hard to keep up with providing resources on that field. You will see some coming from us very soon.
It would be interesting to hear from musicians working on the area of jazz and similar. I have a feeling that alternate chords are not seen in these terms. The diatonic type of view, which we generally see in these essays, is a kind of traditional theory that I first learned when starting out, where the theory books themselves warn in small print that it is a simplified view belonging to a Baroque and Common Practice era, which in itself is extremely simplified.