Update: Every PCM driver is now disassembled with their data extracted. Music and SFX in ASM format. Began some cleanup and further documentation that I left untouched forever.
Technically, most of the zones use the same core object code for Sonic. It's just Wacky Workbench that uses its own copy for handling its gimmicks.
I am happy to say that disassembly work on the stage MMDs in particular will go by a **lot** quicker now, because I have written myself an auto-analysis script for IDA that can comb through an MMD file for functions, objects, Nemesis compressed data, etc. I made a tool that auto-generates a list of locations from some databases I have, and implements them into the script, as well.