One thing I think is important, to optimize any build, is in knowing what a particular juice is supposed to taste like. Juices, especially complex ones, have nuances that will appear at various levels of power. For example, an RY4 may taste very 'tobacco ey', or 'caramel ey', or 'vanilla ey', at various power levels. Depending on the power, one flavor will be dominant over another.
I've been DIYing all of my own juice for nearly 2 1/2 years. I haven't bought a single milliliter of vendor juice in that time. I make probably 15 or 20 recipes repeatedly. I know those juices inside and out; and what they do at various levels of power, and with different devices.
It's why I don't experiment with coil builds much. I don't do dual coils, dual wicks, U wicks, etc. I may briefly fool around with them, from time to time, but not often. I approach coil and wick building with the goal of knowing the flavor profile I'm trying to achieve. To get that particular juice to taste the best it possibly can, knowing beforehand what that taste is. Once I find it; that's THE set up, on that device, for that juice.
although I don't make my own juices, I do know them very well, although maybe not as well as if I made them myself like you. like STATE , I vape mainly 3 different ones and when I do get a set up that seems to work well with them I do remember that exact build, but I never seemed to be satisfied and always think it could be better. I always feel like the smell of the juice should match its taste, although a lot of the time it comes close I , for the most part, am disappointed after smelling a juice and then vaping it, it always smells better then it tastes. I keep thinking maybe with the perfect set-up the taste will be better then the smell.