In my experience, completely dissociative experiences on DMT are something that should (if they are to be attempted) be worked up to in dosage. As far as tryptaminergic psychedelics go, I think vaporized DMT is one of the more difficult to really get something valuable out of. Part of this is that vaporized DMT doesn't last very long where mushrooms, oral dmt, or lsd last many hours. In any case, it really helps to be more than acquainted with the cognitive changes that accompany increasingly large doses of vaporized DMT before going for ego death.