I will save that, I will be needing a way to do this myself soon. We also have a generic flex field that now has like 40 different layouts in it. I’m planning to create an admin options page where you can not only select the post types where this field group is displayed but also select what layouts to display on those pages. I plan to modify the location rules for the group when selecting post types, but your ideas may come in handy for filtering the layouts. It won’t be exactly the same because I’ll be getting the mapping from an options page, but it will be similar.
