Ain't that the truth?
It is hard to filter through the mountain of crap on "thought forms" and "constructs" to get to actual experience reports. It is especially rare to find reports with an awareness of the hallucinatory character of the experience. "Shared hallucination," however, taps into metaphysical speculation that everything is a hallucination, and "Folie a deux" is too specific a psychiatric phenomenon.
I think there is a real opportunity to get some insight into how individual minds work, and how they interact with each other. But, unfortunately, to broach the subject mostly brings out the trolls.