Having had countless cubensis trips and a handful of 4-aco-dmt ones, I didn't find them very similar (and found the latter to be uniquely unpleasant). Perhaps I have weird chemistry, but I'm not alone. I would hate for others to miss out.

I would second this. It might be, though, because it is much easier to overdose 4-Aco-DMT than shrooms. Even most milligram scales don't reliably differentiate between 30 and 50 mg but the trip on the latter would be immensely more intense. 4-Aco-DMT seems also to be much closer to DMT than, say, LSD.