Sorry for the long example scenario, but I believe it gets the idea across. Here it goes. You have note 1 with links and tags. You also have a note 2 and note 3. You embed the entire note 1 inside a heading in note 2. The note 2 heading where note 1 is embedded also contains additional links and tags. You embed this note 2 heading in note 3.
In this simplified scenario, you decide that temporarily you would like to let Obsidian (program wide) treat note 3 as if it actually had the links and tags from the embedded note 2 heading, including those embedded from note 1. To be clear, links or tags from other headings in note 2 would not be shared over. To be extra clear, I should mention that with this mode toggled on, note 2 would simply have all of its normal links and tags in addition to those shared from note 1. Notes, such as note 1, with no embedded content that contained links or tags, would behave normally even with this toggle turned on.
Make this toggle a reality, affecting the graph, tag pane, search, and even plugins such as Dataview, etc.
With the toggle turned off, Obsidian would behave perfectly normally. Thanks!