When linking using the block ID, you need to follow the block reference syntax, which is [[Note name#^BlockID]]. Your syntax missed the hash sign #. Also, if you embed a heading using the block ID reference, the body content of the heading won’t be embedded. We still have to use the Heading syntax here (which breaks if the heading is changed).
When I mentioned an FR above, I was talking about an FR for the Copy Block plugin to have a command to refer to a heading using block ID syntax. But then I ran into that issue above, that to embed the body content we still have to use the heading syntax. So there’s no way to truly workaround the fact that Obsidian won’t update the Heading reference link if you don’t remember to use the Rename Heading command. And I’ll have to train myself to use the command every time I want to rename a header (The Block-reference-count plugin count should help?)
I so wanted to use the Number Headings Plugin but I’ll have to stop now. There’s already an FR for the plugin to update links to heading, but I don’t have much hope that it can be implemented (it probably has the same constraints you mentioned above by the Obsidian devs) (Edit: lol I just read your comment from January saying that the dev said “the numbering NOT be part of the note” couldn’t be implemented. Thanks for exploring this avenue so that I don’t have to.)
You’re good! You’re very active in the community and I’ve benefited a lot from that (for example the CSS repository. Great contribution to the community and thank you so much!).