I would like give Grav a try with a personal project. However, I have my own template mechanism designed to sit on top of a CMS: I would need to use this rather than twig, while still using Grav’s administration backend and plugins. Basically, my template system provides a PHP function to render a page’s html and would in turn need a function to fetch a page’s content from the CMS.
Is something like this, circumventing Twig, possible? Does it even make sense?