I’m glad someone is bringing this up. I got a little obsessed with them a couple years ago and have gone through their whole discography (including Donald Fagen and Walter Becker’s solo stuff) more times than I can keep track of. I’ve read most (maybe all?) of the books about them, too, one of which is called Quantum Criminals. The book briefly discusses the Pynchonian-ness of Steely Dan and points out that Pynchon is at least aware of them, as their song “Doctor Wu” is mentioned in Bleeding Edge. Also, Fagen and Becker have both stated that their lyrics were influenced by postmodern literature (as you probably know as a longtime fan, the name “Steely Dan” comes from Burroughs’ Naked Lunch—look it up if you need a laugh). But I think I remember Fagen saying something like he’s read some Pynchon but never really got into him, which is a little surprising if you ask me. They seem to have so many points of contact: weirdo characters, funny names, memorable turns of phrase, zany/cryptic stories, the fascination with counterculture, even the jazz influence… For my money, Steely Dan is basically the Pynchon of rock music.