I think twist just comes with the territory when you're dealing with persimmon wood. I split a pipe-straight log a while back that had no twist in the bark, and the staves still looked like Sopwith Camel propellers. You can usually heat it out if it's too much, a little twist doesn't hurt anything. Locust is the same way-I've cut probably hundreds of locust trees over the years for firewood, bow wood, fence posts, and all-but i don't think I've seen one yet without some twist in it.