We assume that those around us are conscious, and we have good reason to do so, but we can't rely on that assumption in any experiment in which we are investigating consciousness

This is contraidtory in strictly literal terms. Either the reasons are godo and we can build a technical equivalent or actually we just approve of our stance without ever having any basis to belief so. It is kinda like Turing having said that when in doubt whether agents you deal with are unconcsious or not, it is polite to assume so. But this doesn't have epistemological weight. Maybe consiousness turns out to be a fiction necceary for humans to aknowledge psychology in a similar way that some people need the concept of god to found morality. But consiousness as a mode of social interaction doesn't have import to it's turth.