Structured Data – To reference the person in JSON-LD in another domain via @id

I have a personal homepage, mainly for providing information that I have created and published. I have an info page with information about me. There I created JSON-LD like this:

{
"@context": "https://schema.org",
"@type": "person",
"@id": "https://my-domain.com/about#i",
"name": "the name",
"same as": ["https://www.linkedin.com/in/myprofile"]
}

I also have a blog where I publish posts. I started enriching the blog posts with JSON-LD, for example with blog posting to like

{
"@context": "http://schema.org/",
"@type": "BlogPosting",
"Heading": "An article",
"url": "https://my-blog.com/an-article",
"author": {"@id": "https://my-domain.com/about#i"},
}

Reference to the author with the @I would my website.

  1. Is this the appropriate / intended use of node referencing over the @I would?
  2. This assumes that when analyzing the blog article, my website also needs to be parsed. At least Google's structured data test tool says that Surname Attribute is missing.
  3. What is the best thing to do? Add a new authoring entity to my blog (with a new one) @I would, refer to it from the blog article and link it to my website via same as? Or as described above, but add other data. Both approaches assume that the data is somehow kept in sync. What happens if not?