For what it is worth, while I did make a sort-of tillering tree, I never threw the bow on it except to make sure it wasn't going to blow up in my face. I merely used a micrometer and caliper to check for uniformity in thickness, and the rest just worked itself out.
As for the next bow? We will see
. I'm not in a big hurry to make another, but a stave/sapling could be fun.