Re: the improvisation styles: without theme(s), can sound more like "noodling", a la Hoffman interludes and Cziffra pre-concert warm-ups. Themes, please.
Yes, I'm sure all the jazz greats who played "progressive" jazz were geniuses, but I prefer Brubeck (often derided by jazz DJs as "Richard Rogers" music).
Poly's sixth chords and lush harmonies are present just as in his compositions, kind of like Rachmaninoff: even Rachmaninoff's Bach transcriptions sound like Rachmaninoff. I'm thinking of Manfred Clynes and his computer that detects a composer's unique "fingerprint" as a wave/shape that is the same for any composition by the same composer.
Oh, and "we" would like very much to hear some of that Wangian technique by the longest contributor, used in recordings of standard repertoire by 1) Chopin, 2) Rachmaninoff, 3) Bach, 4) Schumann, 5) Ravel, 6) Scriabin, 7) Godowsky, pretty much in that order.
And before y'all do this again (and "we" do want you to do it again, please!), have (one of) the contributors watch Dudley Moore's video of the almost-never-ending Beethoven Over the River Kwai: https://www.youtube.com/watch?v=GazlqD4mLvw
Probably won't help..."we" like him anyway.