The rafters in my shop are full of maple, walnut & cherry blanks. I will assemble a kit from a reputable maker for a customer, but I much prefer starting from a blank. I have had a few pre-shaped by Fred Miller, but usually just have him inlet the barrel. I am having Dave Keck do one right now.
I was amazed when Fred told me how many recognized builders he did shaping for!
There is a big diff. between just pre-shaped and pre-carved, as in kits. But they do create a lot of restrictions for the builder.