We try to explain the "why" behind the suggestion we make as thoroughly as possible during our review so as to prevent the need for follow-up questions.
If you've got quick follow-up questions though, we're happy to answer those over email.
If you want your reviewer to take another look at your materials after you've made updates, we offer "re-checks" as an option at a discounted rate from a full review. You'll receive a link to book these with your review feedback (both for Sanity Checks and Essay Reviews).