[smacktoward]

> I've seen versions that would do just fine with the separated part mixed in. (They're not just with Granola.)

My guess is that, if you're going to be offering a version with granola, you're going to be designing/fabricating packaging with a separate mix-in container anyway; and since you have to have that package, it's just easier/cheaper to re-use it for other mix-ins that don't technically need to be separate than it would be to come up with another package just for them.