All I can say is: Don’t. Be. Me.
I thought to myself, this clue is easy. I’ve made these units a zillion times. I’ll just sew a scant seam and won’t need to test my seam allowance. I can just finish everything at the machine then head to the ironing board and cutting mat for trimming.
Sigh. That scant seam wasn’t really scant. Nothing to trim on most and some units (the shy ones, hiding under their better constructed brethren in the photo) will probably need to be re-done.