ISO invariant sensors are considered an improvement in sensor technology. This would multiply production costs by at least 4x to go backwards. Stacked sensors include memory and processing on the sensor. Where are you going to put four separate circuits? Why bother doing this at all?

No idea what you're describing. How do you know what subjects people will be shooting during camera production, or even just before the moment of capture (so the right "circuit" can be used)?

This is just matrix metering plus some strange ideas about how sensors work.

Faster readouts are possible by using better materials (copper). It's more expensive so reserved for higher-end cameras. Now you want to spend more to provide a slow readout option? Why?

This is self-contradictory. By choosing a "base ISO", you're "baking in the ISO". Adjusting exposure in raw processing is allowed by ISO invariant sensors. But by having different circuits for different base ISOs, you've eliminated that flexibility. What problem is this supposed to solve?

Most cameras have something called Auto/Program mode. Some cameras have Priority and Manual modes.

This is wishful thinking, and not possible. Each stop is a power of 2. For 17 stops, you need at least 17 bits. But you've specified 12 bits.

Okay. But why not shoot raw? Or set white balance properly in the first place?

What's the purpose of this? You're just adding options with no benefit for users. I can already save more RAW+JPG on a card than I can capture in a full day of shooting. People who don't want high resolution images can already save lower resolution images. HEIF compression is supposed to be better with lower file sizes.