Not handling them for 4 days is no problem at all. Honestly, the snakes probably don't even notice. I'm not sure snakes have the same concept of time that we do anyway, LOL.
BPs are such docile snakes by nature (most of them, anyway) that even extended periods of not being handled usually won't cause any long term issues.
I used to travel quite a lot for business, and when I would return home from a 5-7 day trip some of mine would act like I'd never been gone, and a couple of them would look at me like, "Hey, where you been, and have you forgotten how to thaw a rat?"