I actually have had this, I completely forgot about it though. Every time I take LSA from hbwr I get (pleasurable) brain zaps. And it tends to happen again if I smoke mj the next day.

Yes, I forgot about getting these after heavy MDMA use as well. Once I overdid it quite a bit one weekend and had zaps for a week or two, they felt as if I was falling out of consciousness momentarily like when you are falling asleep but catch yourself before you do.

That and puking up black stuff during the last roll led to a long break from MDMA.

I am not sure if this is the same phenomenon that others have experienced. The best way I can describe what I have felt is some sort of energetic cleansing. It was like I was simultaneously in two dimensions, very aware of "normal reality" while I was having my "energy" cleaned in another dimension, a dimension in which the gravity was much higher. I remember these beings holding me down in this other dimension while my body in this dimension was snapping and crackling and shooting sparks. Afterwards I felt very strong, like long time blockages had been cleared in me.

Should mention this was ~40mg of vaped dmt.

short answer? 5HT2A signalling.
i've experienced it on all the usual suspects, and it was especially intense on ayahuasca.

^^ nope sorry, it is unquestionably hyperdimensional giants

Any really in depth info on this? I've never experienced it, but not liking the sound of it from these posts. What's actually going on here ?

I never really worried about it and I actually find it quite pleasant.

It's never occurred once I regained baseline so I just see it as part of the temporarily alter'd brain signaling typical of these experiences.

We (intezam) have these zaps all the time, also when we're 100% sober (we call them zengs). When we take harmalas these (5HT2A) zengs increase to a pulse. We don't like'em very much because alarm-mind tells us they might be followed by a *seizure..
(*didn't happen tho)

Those "zapps" i experienced are more like a very short break down of all filter-systems, resulting in a short burst of very intense sensory perceptions. Its a complete sensory overload, especially the acustic element. I hear everything EXTREMLY loud. Every sensory channel is turned up to the absolut maximum which is painful and unbearable.
Thankfully it lasts only half a second.

I kind of vibe with the extra-dimensional explanation (and the 5hta signaling). Cus I tried out some Harmala and a lil' Ketamine and had some visions of alien spaceships from different planets coming together to find the outside of the universe and find out about a new dimension that was green and full of stuff. Then 2 minutes later I heared some electronic devices humm a little louder and at the exact place where I was having a little bit of a headache got one of these impressive zaps that last for half a second or so and saw this green stuff/place or space or what have you but actually realistic this time.

Not sure if the Ket is involved but I kind of enjoy meditating and had to stop once because I was having pulses that jolted my body upwards quite powerfully. So like a body zap instead of a brain zap and my muscles go Whoop and tense up for a second. All this along with mildly scary but powerful Sleep Paralysis episodes in the same session led me to take a break from meditating for the night. But when my body zapped; Curiously, I again heared some electronic devices hum a little louder in my immediate environment. I was thinking solar flares for a minute.

Yes, I've experienced this several times on LSD and mushrooms. For me, they were usually triggered by certain thoughts, especially during those brief flashes of insight you sometimes get on psychedelics. It almost feels like Im about to leave my body quickly and forcefully, like a spontaneous OOBE is about to happen.