I don't FOR SURE know the answer to this, but this is my thought process...
Think about it in terms of energy. Every time they eat, they are using energy. Every time they have to strike, and constrict, they are using energy. So to only have to do it once (granted it's larger prey), you are going to get more energy gain from consuming that ONE food item. If you have multiple, they have to keep using energy to kill each prey item, and then to eat it. I would think the net gain would be in larger prey.
HOWEVER, I have heard that because pups are still on mothers milk, there is a faster growth in balls when being fed JUST multiple pups.... I haven't seen it, and I know that with mine.... they won't regularly take 2 meals, so I'd rather just feed one and get it over with. 
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Teresa
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3.0 Dogs (2.0 Chihuahuas, 1.0 Toy Poodle)
1.3 Cats
1.0 Cockatiel
1.0 Indonesian Blue tongue skink
Ball Pythons
0.1 100% Het Albino (Watson)
1.1 Pastel (Sweets and Camille)
0.1 Spider (Daisy)
1.0 Albino (Gormagon)
1.0 Lesser (Wendell)
1.1 Normals (Fisher and Sexy)