In fact the solubility limit of pure cbd in c8:c10 MCT oil, at about 20-22c, is 33%. You can achieve richer mixes, but the excess cbd will eventually crash at some point, e.g. if you add a seed, or smeer the mix as a thin film on a surface. As soon as it start to crystalyse, you can then sort of freeze the whole mix if you stirr it up. The concentration of cbd actually dissolved in the oil will be 33% then.