I don’t think it’s very hard, I just think not enough people care enough about getting an equivalent result. Basically 80/20, but no one will pay for that 20 (yet)

On the topic of emulating old hardware, this reminds me of the Nintendo 64 VRU accessory, which is a mic + voice recognition that was used in games such as Hey You Pikachu. Nobody has emulated the hardware which performed the actual voice recognition, instead opting for modern VR libraries. So while you can use it in an emulator, the performed VR won't match what you'd get with the limited hardware implementation.

  >This is an HLE implementation. I did not emulate the manner in which the VRU does voice recognition

https://github.com/mupen64plus/mupen64plus-core/pull/873

I suspect it is because of hardware limitation. The silver base one actually have multiple layers, not just one thin silicon light receptor layer. That depth and the randomness of the silver particles make the result very difficult to emulate. Perhaps if one can use those staggering focus???