Just some quick note about the progress of the Modular Pattern System in relation to Wordpress
I started the MPS some year ago as a 'standalone (PHP) tool' to make prototypes that easily could be migrated to a WP child theme, relaying on a 'base' theme with the actual code and classes.
As things grew more mature and with the fact I want to create a 'pattern' library and be able to add code to it in simple way I decided to convert the 'base' theme to a Wordpress Plugin. And I'm glad I did that also because pretty familiar with creating plugins for WP.
It gave me the option to add WP Admin functionality that interacts with the front-end, like choosing a framework (e.g. Bootstrap, UIkit) and moreover the ability to update Elements and Blocks without the need for users to use a repo or separate download.
After installing the plugin patterns can be easily added with the use of a regular theme, pretty neat. At the moment I'm cleaning up lot's of code, test it and make it ready so it can be added to the Wordpress plugin repo.