It's interesting how you describe this "zap" of ego death/unconsciousness.
I haven't had that, but I *did* tend to get these sort of longer-lasting fugue-like states fading in an out for as long as an hour.
By which I mean just... blankly staring, no movement, no thoughts. And time would pass me by and I'd wonder if I'd fallen asleep or something but then I'd just realize that no, I had just... stopped thinking.
It didn't feel dangerous at all. I did find it unpleasant though. To me it was just a sort of viscerally-synched expression of the confusion that the drug can produce--it's a strange one in that regard: I find it very "level" in nature. Not manic like LSD or chaotic like tryptamines. More sobering--not boring or uninsightful... just sobering. At its best (hours in, past the peak, but not so far past that you're just wishing you could sleep) it provides for a seriously cognitive kind of psychedelia--actual hard thinking, rather than just confusing delusions of patterns and connections where none exist or where your sober self already would have known they exist.
But at its worst... at the head of the comeup, it feels (to me) like you're being pressed back into your seat under the weight of a heavy acceleration. Like launching in a drag race. Or blasting off in a rocket ship. That analogy exists for DMT because it feels like it takes you rapidly into another world... but the actual sensation of it seems much more apt when describing DOC. You feel it mentally as well as physically. You're wide awake and full of energy... yet unable to move, unable to talk, even thinking is slow and difficult--it's hard to draw your mind to something outside of the raw sensory overload (even though, at least for me, there are never any visuals yet at this point).
Except the launch takes two hours instead of two minutes.
Luckily, you feel *instantly* better once you manage to force yourself to start moving around. Once you're moving, you suddenly feel like motion takes no effort at all, and it's *stillness* that exhausts you.
FYI I've gotten similar states from other drugs, including sunifiram, fasoracetam, and tianeptine. I'd imagine that taking tianeptine with DOC would make that confusion more likely to pop up.