Clare Fischer's chromatic bridge madness - 'Novios' transcription

Here's a little transcription of the bridge section in Fischer's composition "Novios", featured on his album "Machaca" in 1980 (a vocal version came out on the album "Free Fall" in '86).

This section features highly chromatic - bitonal some would say - harmony coupled with a very strong chromatic bassline which moves mostly in semitones. Notice how RH voicings for A13b9 in bar 4 and Eb7#9 in bar 5 are exactly the same yet notated with different accidentals - makes sense theory-wise, but zero sense reading-wise.

[am]

Ok... What is happening here? Very weird progression.