Is there a way to tell if a yielded component's has-block is empty?

I am trying to make a contextual component that can provide a default header when one is not passed in the yielded block. Normally, I could use the has-block helper to tell if a component has block content but this component will always have block content. I think what I need is a way to tell if the yielded component has block content. For example:

<header>
  
  
    <h1>My Default Header</h1>
  
</header>
<section>
  
</section>
<footer>
  
</footer>

I only want the default header to show when the yielded "header" section is empty. I could create a header component which then could use the has-block like so:

 
    <header>
      
    </header>
...



 
     
          
     
         <h1>My Default</h1>
     

Functionally I think this will work but the only purpose of the "my-header" component would be for this "panel" component and seems wasteful. Open to ideas. Thanks!