One data point here. I've taken a few low-to-lowish dose trips. I'm still the same skeptic/pragmatist I was.

When I'd see the walls billowing and more detail generating out of visual details, I didn't think "The universe is alive!" I thought "my visual system is alive".

I did have an experience which-- to the extent I could put it into words-- was that my sense of reality was something being generated. However, it didn't go very deep-- it didn't have aftereffects that I can see. I'm not convinced it was false, and it might be worth exploring to see what's going on with my sense of reality.