Thanks--the paragraph border is one solution I had considered before,
but the appearance with the line extending all the way to the right
(rather than just the width of the text) is not acceptable. It sounds
like I'm going to continue to have to "manually" unapply the underline
for the non-final lines (that solves the TOC problem by having the
default for the style be underlined) and check to make sure the
wordwrap doesn't change when the document is finalized.