I believe it was also done for higan (bsnes) in order to support enhancement chipped games: the enhancement chips had to be collected, decapped, and decoded in order to correctly (= fully accurately, rather than approximately via hacks to try and fit observations) run the game dumps. I think at least part of the process was documented at the time.

I don't know if all the enhancement chips were collected and decoded, as IIRC a pair of them are literally used for a single japanese-only game.

Although for IP reasons the enhancement chip firmwares can't be distributed with higan, so you have to "dump them yourself".