Yeah sure! Given a fixed light radius and a fixed strength level (11), and given that the hardness of the Shimmera is a constant 12, the cost seems to be fluctuating between -2 and -3 with Mistral and the Attuned Drill (Mistal and Drill nerfs/debuffs cancel out).
Btw, are the pickaxes on the lorestone in unlock order or in a pre-set order? If the latter, I think it makes more sense to match them with the order in the pickaxe selector drop-down. Also, speaking of lorestone, could we get tool-tips on the equipment items as we do on the other tabs, as a quick in-game reference?