Not impossible, but again, too much work for the amount of times that a bankswitch scheme changes. I don't know of any emulator that does such a thing, precisely because the need for it is so small.
The Melody is naught but a highly sophisticated bankswitch scheme. It's a single piece of hardware, just like the VCS. It's a coprocessor to the Atari, no different than say the SA-1 or Super FX is to the SNES.
All the information needed to run the "driver" you speak of is already embedded into the ROM itself. Otherwise ie to play Draconian on a 2012 Harmony Cart, you would need to reflash the firmware, but it isn't necessary to do this. Draconian runs on it's own because it was designed for the Melody PCB.
If someone designs a game exclusively for Encore, or some new expansion hardware not yet fabricated, then the gamer would need to buy a new flash cart. This isn't the case however. Draconian runs on older Melody hardware.
But Stella version 4.X runs older Melody games but not newer Melody games, even though the hardware supposedly being emulated has not changed. So the emulator isn't truly compatible at the instruction level. Someone should HiGain or BSNES Stella so when a homebrewer creates something designed for a Melody PCB, it will function samely in the emulator as in hardware.
Lots of Melody exploits to be discovered and lots of patches yet to come for Stella. Besides Melody -> Encore -> Concerto, what other patches, if any, have been necessary to the Melody platform in order to run new games?