Well, I think I can offer evidence that this is indeed the fumarate, or at least not the FB. While I've never tried it, I've always read the sniffing Freebase chems is very painful/stinging. While titrating up, I sniffed about 5mg, and had no stinging and just a mild post nasal drip.
Furthermore, I felt that beginning tryptamine feeling, which leads me to believe it's like 4-aco-dmt not 4-meo-mipt (though isn't proof of course, as really it could be anything.) Then, in a moment of stupidity, which I have a lot of, I took 20 more mgs by mouth 20 minutes later. As far as experiments go, it was horribly designed, considering I have a major tolerance to psychs both longterm and short term (having last tripped only 3 days prior.)
That said I was surprised by the strength of the come up, as I thought my tolerance would kill the trip significantly. Since I hadn't planned any of this except the initial 5mgs, and having not seen another report of 4-PrO-DMT anywhere on the internet, making me "the 1st to try it" online at least, (ignoring anything I've missed elsewhere on the internet,) I mildly freaked out during the come up, and took 4mgs of etizolam. So I can't describe the trip well, other than that the video game I was playing became too complicated and I just watched TV/listened to music. It did seem closer to 4-aco-dmt, then whatever I would guess 4-meo-DMT would feel like (though I can't say I know what that would feel like.) I also had some mild OEVs (which are rare for me without huge doses and/or mixing of substances. But given my tolerance/benzos, I can't say anything concrete about the trip, though I'd bet 10:1 it is an extended 4-aco-dmt vs an extended 4-MeO-DMT (assuming it's one of those two.) I also believe, if it is degraded, it's a very small amount. Typically for a medium trip, when I have waited over a week between trips, 40mgs of 4-aco-dmt works for me, because of my perma-tolerance/large body/crazy enzymes that I've had genetically tested and are super wack. So please no one use me as a dosing guide.
I'll try to give myself at least a full 7 days off before I do another test. And I'll make sure I'm better prepared and can give a better explanation of its differences vs 4-aco-dmt/anything else, assuming I'm able to get to it and aren't too tempted by another chem, lol.
Anyway, just thought I should update. And I guess give the first "trip report." Though I realize it wasn't much of one, lol, I'll try to give a better one under better circumstances. Though I've never been a trip report type of person. Anyways, peace y'all, I hope this proves at least somewhat useful