It says
“This iPhone has experienced an unexpected shutdown Because the battery was unable to deliver the necessary peak power. You have manually disabled performance management protections “
This shutdown happened when we had a cold spell and I was walking outside in -35.
I suppose the battery could be the issue as the restore hasn’t made much of a difference.
"This iPhone has experienced an unexpected shutdown Because the battery was unable to deliver the necessary peak power," is Apple's way of telling you they throttled your processor so as not to stress a taxed battery. However, "You have manually disabled performance management protections" is Apple's way of saying you then went in and turned off said throttling, which you would've done on the same settings page as this message.
If you're still experiencing seemingly slower performance after turning performance management off, though, then something might be up... Firstly, the SE battery can be bad when the battery health even when it measures in the mid-to-low 90s range; mine was, and was about unusable once it degraded further into the high-80s range. When I finally took it in for repair, the battery was swollen (which explained the noise I would sometimes here when pressing down on my screen). I had dropped mine in water briefly at one point, so that could've started a slow degradation of my battery which didn't manifest itself until almost a year later, who knows. Similarly, the cold could've done some subtle damage to yours that is manifesting later (again, who knows; I'm just throwing theories against the wall).
The battery in my wife's SE, though, also started behaving badly in the mid-to-low 90s range, though, and qualified for replacement. (Hers has never been dropped in water, exposed to cold etc.) So, with performance management turned off and your battery health at 93%, it could very well be time to have your battery replaced.
Before getting my own battery replaced, I did download Coconut Battery to my Mac as a way to independently measure of my iPhone's battery health... it seemed to be way more accurate and showed a much less healthy battery. So, you could try that to see if it sheds any light on the situation.
Regardless, with your battery showing performance management [throttling] kicked in and showing a not entirely healthy 93% health rating, you could try taking it into the Apple Store to see if they'll replace the battery. If replaced, chances are you probably see improvement. (They can also run a diagnostic over the phone if you don't want to spend time at an Apple Store right away.)
OH, ALMOST FORGOT: Have you upgraded the iOS version, recently? Increased battery drain is always a thing for the first few days after an upgrade as the phone is busy reindexing files, then it calms down a few days later. I saw another thread on here about iOS 12.2 causing drain on the iPhone SE, though it's hard to tell if the issue is "real" since no one says how many days/weeks it's been since they upgraded to the latest version. (I'm still on 12.1 so I have nothing to add to that conversation, at the moment... though it sounds like the 12.3 betas might be gentler on the batteries than 12.2.)
