I think if that dont hold it, not much else will. I've never done a thread wrap like you did, just because I like to hide the patch, but it sure looks like it will hold well.
Just curious Justin, do you think it lifted a splinter in that spot because of the way the limb is bending at that spot? Or do you think it was from another reason. Also, did you check the tiller before and after the wrap, a comparison of sorts?