As long as you are buying frozen from a reliable source there is no problem with how healthy it was. With my baby BP's I found that hoppers were too rambunctious and scared the hatchling and it wouldn't eat. Gave it fuzzy, more like crawlers and they ate. After a couple meals like that they new exactly what to do with a hopper. All depends on the snake.
We do have a snake freezer, not that I care but hubby was totally disgusted to find a bag of rats next to his chocolate ice cream