This looks great Tom. This might resolve some of the junk code brought across from Blogger too? Will have to investigate.
WordPress filter to auto-linkify @names for Micro.blog
This is another great deep dive Alan. I have not quite got to the stage of carving things out in the backend, but have started down the road of a Child theme thanks to your help. I am interested in adding your solution at that level. It really bugs me how the default oEmbed bakes in the parent post.
P.S. Am I the third reader or a lucky forth?