If this guy is representative of what they look like, I wouldn't assist feed yet, although other folks' mileage may vary.

Showing interest is a good sign, that they're not taking means something isn't quite click. It's not unusual for baby BPs to not take rat pinks. Some people think it's movement, some people think it's the lack of fur, some think it's lack of smell. You can try leaving the pinks in with some dirty mouse bedding to help them pick up scent.

I still suggest lowering the temperature. By several degrees. Take the hotspot down to 88-89. Do they babies use the hides an overwhelming majority of the time, or are they frequently out, like the little guy in the picture?