There's still the question of whether experiences arise based on complex interplay of matter (incl. neurotransmitters) in the brain.

Introducing a surge in this particular property clearly has an effect on consciousness. Whether we relegate that occurrence to a status of being merely mechanical, or otherwise, is going to reflect our worldview.

and calling the above commenter's materialism "convenient" is a convenient way to avoid substantiating your position IMO

The point is that it is convenient to simply dismiss experiences of that nature outright based on the view that our baseline experience of consciousness is solely true, while other so-called "altered" states of consciousness are fallacious. Such an attitude is indicative of a materialist outlook.

Is there any reason to think that DMT is substantially different from other hallucinogens

Yes, it is a different animal entirely.

DMT involves accessing the bardo or something?

This is not a claim that I made. Although since the bardo can be accessed while still clinically alive through certain practices, a claim of that nature isn't that much of a stretch.

It just seems to me the line is being drawn between experiences that involve contacting other supposedly beings and those that do not.

I'm simply noting that it is common to receive reports of having interacted with other intelligent beings from those who have had DMT experiences. I have friends who have also reported this. It is a widely occurring phenomenon.

What do you think about DMT in respect to other hallucinogens

It is radically different from what I can tell. And I have heard this from friends who have tried it. One friend in particular who is very seasoned in terms of a long history of involvement with entheogens, said that while taking mushrooms or lsd for example, he felt "messed up" in the sense of being under the influence of a psychoactive agent. But this was not the case with DMT. With DMT he reported that he felt completely lucid and normal, and the world around him simply fell away. During the entire experience he felt completely normal and not under the influence at all. The only thing that changed was his surroundings, and he was convinced that he either traveled somewhere else, or simply saw a facet of reality that is always present yet cannot be encountered from the standpoint of our baseline everyday state of consciousness. He too reported interacting with other beings who answered questions for him.