I usually use the first line after metadata in my notes by putting the link of where it comes from. So when I transclude such note into another one, the embedded content also shows that first line, which is kinda inconvenient for me.
What I’m trying to do
I would like to all of my embedded notes have hided their first line.
Easier than that: change your content priority. Put source where it comes from after the content.
Even in academic writing where citation is critical, the content is more important than where it comes from. That’s why citations are captured in parentheses at the end of the line or at the very end of the article.
Changing the order to show the content first is also better for your system because you don’t need to customize your instance of Obsidian to do it.