The pipe metaphor is doing a lot of good work here.

I’d agree with the part you’re putting on integration. In the MDMA-assisted therapy trials you’re nodding to, the drug is the wedge, not the answer. The Mitchell et al. work in the New England Journal of Medicine is useful because it keeps the emphasis on therapy: the substance can lower the threat of remembering, but the actual work happens when someone can stay in the room, name what’s there, and connect it to a workable boundary. That sounds a lot like what you’re describing. The flood doesn’t vanish. The boundary becomes visible because the nervous system can remain anchored long enough to notice it.

From my paramedic side, I’d frame “empathic permeability” as resonance without enough down-regulation. You can pick up other people’s states quickly, which is useful in a scene, but if the regulatory side isn’t running, the signal stays in your body long after the scene is over. A shutoff valve would be less about shutting people out and more about having a repeatable way to say: this is theirs, this is mine, and I can respond without absorbing the whole load.

Autumn makes that easier to notice, I think, because the season is already asking for less open surface area. What would a workable boundary look like for you in practice? Is it a phrase, a pause, a physical cue, or a specific limit you can set before the interaction gets too intense?