There is a newish (since version 2.53) conversion setting in Calibre that I haven't looked into much yet: Look & Feel > Transform Styles. It allows you to set more sophisticated rules than simple filters.
https://manual.calibre-ebook.com/edi...css-properties
I haven't worked how to do it in a way that handles all cases where the publisher has used different types of unit (px, pt, em), but it might be possible to create rules that would only remove line-height properties that set the height strictly greater than 1em and less than about 1.5em, which would be a big improvement on simply removing all instances of line-height.