It is already quite straightforward to convert analog instruments to a synthetic display, and it wouldn't be too hard to use that technique to generate a state

It is already quite straightforward to convert analog instruments to a synthetic display, and it wouldn't be too hard to use that technique to generate a state space to quantize against. But you really need to be able to pull each meter apart to make sure that you can enumerate all possible states, otherwise you'll end up with undefined input. You can do it in software by fuzzing inputs, but stimulating hardware to extract state is another story.