Obviously each person's experience is their own and understanding, wonder, enlightenment, etc. can be obtained regardless of the experience or the drug of choice.
I just think too many people pollute their experiences with what other people put forth and their own expectations or desires instead of focusing on finding their own path naturally. While I think it's good to hear trip reports from folks, hear about their experiences and what they saw, felt, realized, etc. while on a certain substance. . .I also think one should make sure not to go into a journey looking for a certain thing.
Now, that's not to say you can't take a trip on acid and find a higher intelligence. I mean it in the sense that, IMHO, you don't need to go into a trip thinking that you just HAVE to see machine elves like Terrance did. Or that you HAVE to reach the 4th plateau on Dexter and see God/aliens/whatever.
Are those experiences possible? Of course. Are they or can they be life changing and fulfilling? Absolutely. Do you need to burden your trip with a bunch of expectations, preconceived notions, and all sorts of other baggage? In my opinion, no.
Personally, I think the more you expect out of a trip the less you'll actually get from it, because you'll be so concerned about seeing this or doing that, that the true experience will completely pass you by.
I suppose this has been a bit of a rambling response, but my main point being. . .yes, contact with "other entities" is more than possible on things other than DMT, but it shouldn't be why you choose to take a substance and the sole thing you are searching for and planning to get out of the experience. Just let it ride and see where you get taken.