I've read the same but would exercise some caution if going that route. I've heard from a few keepers that BPs will get hooked on gerbils and refuse any other feeders. Since gerbils are a bit more expensive than rats as they're not typically sold as feeders, you may end up with a bit more expense for upkeep than if you were still feeding rats. Also if you ever needed to rehome your snake for any reason other keepers may be hesitant to take it if all it'll take are gerbils.
Nutritionally I don't know if there's much of a difference, but would rather someone with more knowledge on the subject comment. My only concern would be that while you could get her eating regularly which is the goal regardless of cost, does she then refuse any other feeder and make you buy gerbils for the next 30+ years.
Also just to add after re-reading your initial post, rat fuzzies and pups are probably the size your BP is on currently. If you have issues feeding F/T feeding a live fuzzy or pup, with your supervision of course, shouldn't pose much if any risk to your snake. Just my 2 cents.