>Consider that incandescent light is not substrate independent - it requires tungsten or some other specific chemistry that works.

Light is a physical thing. Physical light is interesting/useful because it interacts with physical objects.

Intelligence (or "intelligent behavior"; going to just talk about that and not exclusively-human-level for this comparison before touching "consciousness" here) is usually characterized by the way people/things choose to act. By the information (such as the information encoded in a series of nerve impulses by a brain, or the purchase and sell orders by a trading bot) produced in response to the inputs. A simulation of intelligence that produces the same information in reaction to the same inputs as a different physical implementation shares certain essential qualities that make the simulation of intelligence as interesting as other implementations, as long as you can translate the I/O into physical/worldly interactions. As compared to the much less usefulness (or restricted usefulness) of a simulation of a light bulb (unless you can translate its output into physical form, but the main way we know to do that is with a physical lightbulb or something even more expensive).

Now it's possible that maybe consciousness doesn't share this same substrate-independence as intelligence; I just think there's a likely connection between intelligence and consciousness and that extends to qualities like this.

>Could consciousness gather around local "concentrations" of hyper-connected networks with a lot of feedback circuits in them?

Does it influence then influence the particles to act physically (or virtually) different then? The rules it uses to identify particles to manipulate and the ways it manipulates them would then just be considered a part of physics. (It could be that such a "consciousness field" could enable higher classes of computation that Turing machines are capable of. The natural thing would be to then try to figure out if a computer could be built that takes advantage of the consciousness field. But then... would an algorithm that uses the consciousness field to calculate a specific value and then complete be considered conscious or to have the moral-standing like a human just by virtue of interacting with the consciousness field? What about a computer that produces intelligent behavior and interacts with the consciousness field? I feel like people uncomfortable with this would then propose the existence of an undetected consciousness² field that gives humans something that makes them unique that the computer doesn't interact with, because it seems like that's the main reason to propose a regular consciousness field to begin with.)

If the consciousness field doesn't manipulate the particles but just passively exists near them... Then it can't have anything to do with why we talk about consciousness. Some chain of thought occurs in our brains that results in nerve impulses that makes us open our mouths to talk about "consciousness", and a non-interacting field doesn't have to do with that process by definition. Maybe it could exist separately, but it doesn't provide any answers in conversations we have.