Note that the TOC use of Styles for levels uses by default the "Outline
Level" which can be set in the paragraph formatting for the Style or
text. If you edit (or replace) Styles so they are all Body Text level
except for those you want in the TOC (for which you can designate up to
7 levels), your TOC will automatically populate the correct level for
the Styles. You don't have to reset them each time you redo the TOC.