I missed that about the shortening. Sheesh.....
The crumbly is cutting too late in that case maybe.. High coconut oil soaps take less time to harden up. It also means 8% superfat isn't enough. @Auxotroph have you actually told us what the ingredients of your shortening are, and at what percentages? As I said earlier different fats require different lye amounts, regardless of concentration. Take a pic of the ingredients list or something..
He's actually got about a 50% SF the way he's doing it. Which will be rancid in no time.