To think you can never get rid of hypervigilance

Ah, yes - the exaggerated startle response!!
💥😱💥

I used to wonder why people couldn't see the things I did. (Like, for instance, that really popular man in a group or organisation who everybody thinks is just a loveable maverick... but you realise that he's a bully or a predator who flies under the radar because he picks on the lone one, the small one, the one with no social capital, on the edge - so there's no come back for him.) Now I realise that they don't see because they literally aren't trained for this.

I try not to let it change too much about my behaviour in the ordinary run of things. If I get a blast of someone else's pain, it doesn't have to become my responsibility. Or if I need to remove myself, I will do so. I have certain workarounds: I try, for instance, never to be the first one in a venue and therefore responsible for picking a table - because I already know where the doors are and which way they open, but if someone else makes the decision, I don't have to make the calculation over where is 'safe'. I'll just roll with it.

I hadn't heard about the Botox. I'm not sure I'd do it though.

After lots of therapy to help control my stress levels I now think it’s my super power. I can quickly judge character which enables me to form relationships in work quickly, which is perfect for my job. I have no difficulties in reading people in teams meetings which I think a lot of less vigilant people struggle with. I find an online meeting no different to an in person one. I can also spot a wrong un a mile off. I’m easily startled so don’t like anyone walking behind me but apart from needing some down time every now and again I manage really well. I have a very understanding DH and DCs who know to back off of I say I need 10 minutes to myself. I think if you can get the stress off of under control it’s not a problem. I do a lot of meditation 🤣

I think it's possible, but admittedly it's not something I've managed to achieve yet. I'm seeing a somatic therapist, and working with her has made me far more aware of the many things I do automatically (abusive childhood, unattuned parents, CSA) -- not just hypervigilance, but shallow breathing, clenched jaw, making myself small, defensive posture, capacity to ignore bodily cues like hunger and tiredness until they're screaming etc etc. I'm in my 50s too, and have been doing these things since early childhood, but working very hard in therapy is making me aware of them. Awareness is the first step to undoing. And it's difficult, I won't lie. But I am relearning how to breathe, and to ground myself in something other than 'What is that flicker of expression on the other person's face saying? Am I safe?'

So you might need something other than talking therapy.

@MargoLivebetter Yeah its wild there is an increasing body of research about it, I had no idea until I noticed a change in myself.

I don’t do it when I’m alone in my house with my cats.

so I use that as rest time.

So after a difficult childhood I struggled with this as well and tried all sorts to move on from it. However it was after getting botox for severe migraine (something that likely was triggered at least in part by my hyper vigilance) that I gradually noticed an improvement. You have to get the glabellar / frown muscles done as this stops the feedback between your facial muscles and the amygdala i.e. the emergency warning centre in the brain.

It doesn't make you insensitive it just sort of dampens down the high alert stress state over time so that your at more of a normal level. Might be worth a shot or at least looking in to?

For me, it’s the one part of my PTSD that I don’t think will ever leave me. And I’m okay with that to some extent; I suspect that I might, in part, cling to it as it gives me a sense of control (even if I know that I’m not in control of it).

Short answer: I don't think it's possible.
Longer answer: Why would you want to switch it off? I'm the same as you, in my mind 50s with a heap tonne of trauma in my childhood, going back to early years. The hypervigilance is exhausting, but I don't know how not to do it. It's not conscious. I get blasts of somatic empathy too. I have to factor in some time every week to be completely alone, otherwise I start climbing the walls with it. On the other hand, I always feel that the majority of other people seem to be walking around with their eyes shut. So I've started to think about it like a superpower.