i don't know anything about the concepts. have some experience with altered states (obe, trance, weird dreams), but it's a vast territory of possibilities, so you have never seen it all, and it's hard to judge whether you know what someone else is talking about, when they use similar language (astral projection etc) .. quite frustrating, which is one of the reasons i don't care too much about "research"
i never took DMT but other dissociative drugs (salvia) and i had dreams, that resembled the salvia experience (as unbelievable as that may sound, if you know salvia), i'm inclined to believe that those dreams come with DMT secretion (cause DMT is formed in the pineal, if anyone has missed that fact), even if that doesn't actually "explain" anything. happens in the first 3 hours of sleep, if it happens. rather normal shit, i guess, just not something that is usually remembered.