Hey Tom!
I see that GeneratePress has some basic blog schema markup built in, which is really all I expect, because you can’t add everything… however, I’m really curious why you are using Microdata (hatom) markup vs JSON-LD.
1. JSON-LD is actually the recommended method by Google. (https://developers.google.com/search/docs/guides/intro-structured-data)
2. Google can read JSON-LD data that is dynamically injected from Javascript code and embedded widgets.
Both Google and Bing support JSON-LD and it seems to be where all the schema markup is going. Perhaps for basic sites, JSON-LD doesn’t really differ that much over microdata (other than the language). But was just curious if you had looked into this at all 🙂