It turned out, even with a firmware update months later applied to it, that whenever it gets rebooted, I have to do the above movement until it finally decides to boot, and it's random. Sometimes it takes a few spins/flicks, sometimes I'm doing it for minutes on end.
I confirmed this isn't a red herring by leaving it in its frozen state and motionless, and it would never recover, even 24hr later.
This was the second Pine purchase of mine, the first being the PinePhone Pro, which A) I couldn't get activated on AT&T (not Pine's fault with the 3g phase out and whitelist approach, but I digress), and when I used TMobile, I couldn't make a call with it without having audio problems or etc.
Look, I wanted to support them, and the idea of less expensive open hardware/software, even if it meant rough edges, but completely non functional for even the most basic usages... I might as well just build my own and understand all of the reasons why something doesn't work instead of spending days or months getting it to do what it said it would do on the tin out of the box.