Well, the problem is that neither outfit is actually fit to the figure. Just parented. So you would end up posing the figure first and then having to pose the clothing items all over again to get them back on her.
At that point you load things like shoes and socks twice and delete the unwanted bits in both copies and then go in and parent things to the individual foot. I do that all the time with V4 shoes and boots on Genesis. It's a hassle, but it works as well as it needs to.
Actiually, for a sleeper, I think I would probably give this one a pass and go with Mada's old Rabbit's Tales for MilBaby3, which doesn't have nearly the issues of fit, even though her sleeper doesn't have attached feet. (It does, however have a bunny hood with ears -- and a tail!) And even though it would also have to be scaled and parented. It at least is shaped to go on an actual baby, even though a different one.
The issue with this item is that Kit is a 'Toon, and her proportions are strange. She has a much longer and broader torso, while her limbs are short and spindly. And she stands splay-legged. Or at least the sleeper does. Trying to get the legs together tends to break the mesh. And the legs still end up too narrow for Luna's thighs.
I just got home, and have a couple of things to deal with. But later on I'll have at it with Rabbit Tales and CupCake and post them as well.
I was rather pleased with the way twiddling with the transparency worked for the hair. Mind you, I don't know how well the method would work with darker hair. This is the old AprilYSH Blaine hair in the lightest blond that I have for it. Scalp at 33%, Hair 1 at 25% and Hair 2 at 50%.