I must sadly report that sideloading the beta did not solve the issue- I got a little more functionality out of my phone on the beta (in that I was able to get into settings > connected devices), but it still crashed shortly thereafter. Inshort, a difference of maybe 10 or so extra seconds. I could be imagining it, but it seems that trying to do things shortens the time to the crash, which would make sense if this truly is a memory issue.
I'll also note now that the phone gets noticeably warm just on boot up, which could just be a pretty obvious sideeffect of the CPU hauling ass to allocate all of my memory as fast as possible, but I figured I'd leave it here.
My next hope is the security preview release, which @de0u mentioned you could get by editing the url on the release web page, and while I know what you mean when you say editing the URL, I don't exactly know what to edit it too. What exactly is the URL for the security pre-release build?