I'm curious about the best practice for adding custom CSS rules for my header and footer. Currently, I've placed these rules in a <style> tag within the custom header block. However, I've noticed there's also a "custom CSS" block in the theme editor.

Are there any advantages or disadvantages to using either of these options? Could there be implications for caching? Perhaps the custom CSS block saves the rules as an external file, which might be preferable to inline CSS in the HTML?

The custom CSS in v5 will be inserted into the header as a <style> tag, so it's essentially the same thing.