My oldest child is 14. We have been doing quite a rigorous English program. We just need a break from it and need something good yet gentle that can act as a review while maybe still adding some new concepts. I was considering having him to through all of the ULW books doing four lessons per week. He is used to doing English every day anyway. Would this be reasonable?
ULW works alongside Spelling Wisdom dictation books. You could see the samples and try to place your student where they fit best. Book 1 may be too easy.
You could consider some other gentle, CM inspired language lessons like Simply Grammar or Language Lessons for the High School Student: Grammar Review and More available at Queen Homeschooling or Rainbow Resource.