Use case or problem
This feature would be helpful when you want easily linkable blocks/headings as well as consistency in the process regardless of where the blocks/headings are moved.
Proposed solution
Firstly, I understand that moving or extracting a block/heading into another note will break links to the block/heading. A solution to that is outside the scope of this request.
What I am thinking of is a middle ground between atomic notes and blocks/headings via block/heading aliases. If blocks/headings allowed you to define aliases, you would be able to more easily find that block/heading by its alias when trying to link or embed, regardless of a changing block id or heading name. So in a way it would assist with any difficulty remembering the names of headings that have been changed.
Of course, in the case of blocks, you could define a custom block id, but this workflow can feel brittle and exacting, and dependent upon no use of spaces. Plus you need to remember which note it is in. I see avoiding this limitation as one of the major improvements gained with this request. After extracting a block/heading, the process of linking to or embedding that block/heading would be the same as before via the alias, thus making the block/heading feel more atomic. However it is important to remember that after extraction you would still have to fix the broken links (see links below).
Related feature requests
Some relevant requests: Note Composer: links to blocks and headers should be updated when extracting, Automatic/inline update of links to headers and blocks when they are modified (no extra dialog window)
Thanks!