It's possible when combined with some multi-site features of WordPress, an mu-plugin could enable worker mode with WordPress. Though, I'd have to contact my old employer (Automattic) to ask if they would be ok with me using an approach used on WordPress.com, which I'm fairly certain is a 'trade secret.'
You won't notice much performance benefit (because WordPress doesn't support worker mode yet), but it is simpler to run and deploy (single binary) and you get all the benefits of Caddy out of box too, like TLS automation.
