Unfortunately there's a bug with the targeting but I managed to find a solution. Currently the script executes in the footer and tries to obtain the categories using get_the_category() and tags using get_the_tags() but because the footer is outside The Loop, these just return a subset of all categories and tags.
The fix is simple, for categories (around line 230) and tags (around line 247) in dfw-init simply access the wp_query and insert the ID as a parameter. The code should look something like:
global $wp_query;
$current_page_id = $wp_query->get_queried_object_id();
$cats = get_the_category($current_page_id); // Existing line with param added
...
global $wp_query;
$current_page_id = $wp_query->get_queried_object_id();
$tags = get_the_tags($current_page_id); // Existing line with param added
I hope you keep working on this plugin because it's a great idea and otherwise DFP is a headache to implement in WordPress without creating a Custom Theme or Child Theme.
https://wordpress.org/support/topic/categories-tags-bug-and-solution?replies=1#post-7127312