CBC inhibits the reuptake of anandamide which is the endocannabinoid resembling THC naturally produced in the human body. I have had the same kind of experience using those percentages (10-20%) and I have been tempted to try at making my own blend with minor cannabinoids as well.

As someone who used to try moderating THC use by switching out to a CBD blend I do think there isn't just one type of high. My body has been completely relaxed on a pure CBD vape. I think the studies suggesting CBC to inhibit reuptake tracks because it seems there is a ceiling. Lower percentages around 10% seem less potent versus 20-30% or higher. But that's my experience. I have tried all the possible different percentages.

I wouldn't bet on being able to make a blend that would pass a test because there can even be false positives with CBD. But I think it's worth trying. I know pure CBD can be very relaxing. Maybe a blend that is 85% CBD and 15% CBC would be good.

Agreed CBC is more than just a good thinner. But it is really good at that too. A good blend can be poured perfectly at room temperature.