Nothing is unnecessary if it makes you feel better about feeding your snake, but this:
Is a possibility, not a common occurrence. In fact, if you feed the proper size prey to the proper size snake, it actually happens very rarely.
And before you say, "but what about when they're in blue?" I have one that I have to feed in complete darkness, and I'll be damned if homeboy never misses. Somethin' bout' dem' heat pits Yo!