Yeah, I'd just wait a week and try again. At that age it's important to get him eating, but I assure you he won't starve himself.
Just stick to the basics for now: no handling, minimal activity in his enclosure (spot cleans, water change), and keep an eye on temps.
It seems your husbandry is dialed in and on point now. So as frustrating as it can be, try to be patient.
Great work picking up on his head poking out as a sign of hunger. That's typically a good indicator, but obviously not set in stone.
But that's exactly how I feed my adult BPs. I basically wait for them to "tell me" by displaying that behavior on consecutive nights. If I see it two nights in a row, I offer on night three. Works like a charm.
I might wait til later at night to try again though. And make sure you're getting the prey warm enough. You want to aim for around 100° focusing on the head. Since pups are pretty small, they cool quickly too, so it may require re-heating once or twice.
It sounds like you're on the right track. Just try and be patient. Good luck!!
- - - Updated - - -
No, not at that age.