Debugging shipping build 4.20

I’m in the enviable position of having zero errors and warnings during PIE, but when I create a shipping build, it crashes 100% of the time after a short while and not in a consistent spot. I’ve been googling looking for info on debugging shipping builds, with a lot of vague talk about adding lines to target.cs or the “build file” and everything I try seems to result in it failing to build, so I’m obviously not adding these lines in the right places. Does anyone have a set of working instructions for 4.20 that turns on logging on shipping builds so that I can get some logs about this crash? The only thing I’m seeing is “fatal error”. I’ve built this project several times, so it’s something I’ve added since the last build, but nothing jumps out at me as a problem, especially because there are no errors when playing in the editor.