I usually feed my adult colubrids roughly 10% of their body weight per feeding. I'll sometimes feed two smaller prey items if I have an abundance of them or if I want to offer different prey items. Since my kings prefer mice over rats they get two (30g) jumbo mice, or a 30/30g chick and mouse vs. a small (60g) rat. It's the same amount of food just smaller bites

. I can't imagine one or the other being more stressful on their digestive systems so again, it's all about choices. There's no right or wrong, just different methods that hopefully achieve the same results of keeping our animals strong and healthy for many years to come.