Really surprised this topic didn't come up anywhere. I couldn't find anything in the linked repositories either. I guess there's no self-modifying code due to it being mapped into the address space from a cartridge?
You definitely do need code execution from RAM for high-fidelity emulation. How else are people going to implement Flappy Bird in Super Mario World? :) https://www.youtube.com/watch?v=hB6eY73sLV0
