After doing a little bit of research, and checking and seeing what works and what doesn’t, I can confirm that Google looks at Wikidata’s ‘official site’ data entry for any given person, to determine what the Entity Home is on the panel. If you put a website in official blog, it is superceded by official site.
This, of course, can probably be set through other means. But, it’s kind of sad that Google is cribbing so much material from Wikidata.
the more you know