Okay nevermind, it has nothing to do with my base. Even moving away from it causes a crash (though it does take longer). Evidently my save has just broken and I'll need to start over (unless some sense can be made out of the crash logs).
It's near where the lifepod starts out, at an intersection of the grassy plateaus, creepvine forest, and safe shallows. I built it before the precursor update, but even after that patch dropped it still worked fine for a while. I've been to and from…