Dan, since you're primarily on WordPress, if you weren't already, you might like to be aware that most of the principles behind WithKnown stem from the indieweb movement. You can find some information specific to WordPress at https://indiewebcamp.com/Getting_Started_on_WordPress.

Most of the field of plugins specific to WordPress can be found by installing the base plugin https://wordpress.org/plugins/indieweb/installation/ which will give you a simple interface for installing the others you'll need to plug in to get functionality similar to WithKnown. Perhaps this might give you the best of both worlds?