I have, in my yard, 2-42' 7"x9" top plates, they came form the same log, a 9"x14-1/8" timber. The joinery has been cut, they have a bow in them, about 5", I will take it out with a come along when the frame goes up. English tying joint, wall raising, starting at one end and setting the trusses down the building pulling or pushing the wall as needed.
As Ken mentions, scribing can get around some of the issues. In other words they can be used in certain situations. You could but the bow up.
Jim has some extreme examples, nice to see what you could end up with.
Tim
