Good reminder to post an update!

It turns out my issue was the low pressure fuel pump intermittently failing - diagnosed by just hitting it with a socket extension (you can -just- access it through a small hole in the shroud) during a period where it wouldn't start (or pump fuel out the quick connector), and it whirred into life. Ended up pulling it apart, and the brushes were worn down so the springs weren't providing the required preload for a good connection. New fuel pump installed, and haven't had an issue since.

Good luck with your issue!