Well, I've finally come to accept the flaw as a "design element" and to have fun with the patterns and colors that are emerging! The result will be beautiful towels.
I'm using a mix of 8/2 unmercerized cotton and 10/2 mercerized cotton in the towels. I wonder why the weaving yarn companies don't make the matte cotton and the shiny cotton to match in size exactly, but oh well, I'm using them together anyway.
Currently, I have 3 towels almost done, and there may be enough warp to weave a fourth towel.