Okay, so the exclusions do work – or to some extent they do for sure, the code gets there.
Next thing to figure out, that are all 7700 items queued to index? If they are of a different mime type, then it’s not included.
Is there a way I can access the website and this custom code to edit? Maybe I can try to debug it via some verbose outputting to see where it fails or what exactly is happening under the hood.