I think the opposite is true. FC has a ton of extraneous information that is unlikely to show up anywhere. I'm like 75% through Uworld right now and completed NBME and while FC has helped, so much of FC is devoted to brute force memorization of everything. No question is ever going to be "complete the pentad: seizures, mental ******ation, ataxia, hamartomas". Having an intuitive understanding is way more important than brute force memorization.
Also, never ever flag anatomy or embyro on FC. It's just a waste of time. The anatomy on NBME 6 was so damn straightforward and even the anatomy on Uworld is pretty chill.
edit: This is what I'm talking about "What is the most common cause of dilated cardiacmyopathy? Ans: idiopathic although some can be familial" This tidbit has zero learning use and no board exam is going to ask that question.