On the latest version you should be able to shatter higher rarity cores into their lower rarity versions by Ctrl + Right clicking them on the Material Inventory.
Ah, I see. I went through all these hoops trying to work around it, when a fix was already in place. Sorry!
On another note though, is there any way to view a parties total luck/fortune/fate/wealth, without having to calculate it manually? If not, are there any plans to make this more easily visible?