Although this is a really great idea, investing in a few colors of 2 oz bottles is tough for me. My process involves typically making a colorway that I think looks really great and then only running a single batch of caps in that colorway over several sculpts that I don't really revisit at latter dates. As nice as it would be to have an exact match for carbon orange or something like that premade, I don't know how much I would actually use that single color. But again, this is just my process here.
I don't know whether or not this is even viable, but a dream kit for me would be a set of like 20 or more colors in really small amounts, like half ounces that I could mix further but have a solid range of colors to just run with already. 2 ounces on my end would last forever.
Hopefully that was at least a bit helpful, I'll for sure check back and see how this unfolds.