Problem with guillemet character in feed titles

I recently had to create a MailChimp RSS feed campaign for a client and the guillemet, double bracket, character that separates the blog name from the feed name was not being reproduced properly in the newsletter.

MailChimp support says this is because the guillemet is not a standard special character.

It took me over 5 hours to figure out a way to remove the » from the RSS titles without changing the core wp-includes files. FYI: The #9 comment from this post ultimately worked for me: https://www.itauthor.com/2009/03/06/changing-your-wordpress-rss-feed-titles/

I’d like to suggest that the guillemet character be changed to something more hassle-free such as the pipe, | ,or even a simple dash, – .

Thank you for your consideration!