I'm happy to report that it works like a charm, with zero configuration or fuss on my part. Brilliant!
And when checking the profile of Janis Elsts, I see that she is also the author of the very useful plugin Broken Link Checker! Nice work, Janis! Thank you!!
I really don't need the pro version of Raw HTML for my purposes, but I'd like to express my appreciation with a donation -- so I hope you'll add a "Donate" link to either your site or plugin page(s).
Thanks again for making life a little easier for the WordPress community!