Comment by hombre_fatal

> Is it really necessary to highlight the heading at all?

You should be able to take a given UX and ask yourself if it can be improved.

A table of contents that tells you where you are on the page is useful.

Here's an implementation: https://getbootstrap.com/docs/5.3/components/modal/

On desktop, the table of contents on the right shows you which header you're on.