Super cool. Reminds me a lot of playing around with the generated bleeps and bloops in PuzzleScript too (perhaps there's shared lineage with Sfxr there, but don't remember off the top of my head). Big fan of the preset generators for adding good uncertainty to the creative process.
Yes! PuzzleScript embeds a JS rewrite of Sfxr, and the PuzzleScript "sound codes" are seeds for a random-number generator which produces all the other sound parameters. I initially considered a similar model for Dfxr- or potentially even using PuzzleScript-compatible sound codes- but that wouldn't make it possible for users to save sound effects they've manually tweaked after generation. Dfxr instead packs all the audio parameters into fixed-precision numbers and Base64 encodes the result. The codes are longer, but they can equally represent random presets or manual edits.