Schwarz and Co. at Lost Art Press have some strong opinions on modern thread
boxes. You can find them by doing a search for “Lost Art Press blog thread”.

Beall Tool Co. sell dowels specifically for threading in limited sizes and wood
species. Not the cheapest, but may save some frustration if they have something
that meets your needs. https://www.bealltool.com/products/threading/dowels.php

Phil