So that experiment is changing themes was a bust. And I’ve gone back to where I was before. That theme I had tentatively installed suppressed some HTML. (Strike and Insert being the straw that broke the camel’s back.) The theme I currently have active also suppresses some HTML, around the formatting of lists, which is why I embarked on that exercise in the first place.
I suppose this means I need to pay something for running this blog, if I want to be able to control the Cascading Style Sheets or at least pay for a premium theme. That means, I have to consider not paying WordPress, but paying someone else as well.
I hate it when the free ice-cream sucks.