Is there any way we can tweak the Spam blacklist filter to block images that match blacklist list entries while $wgAllowExternalImages is set?

Right now when $wgAllowExternalImages is true, the parser is converting the links in internalParse to images, which is expected, but if those images match something in the blacklist they won't be blocked. These images also don't show up in out->getImages.

If we could check the spam blacklist against something a little less processed than external links, it might work. Is there any reason why the blacklist isn't just compared to the raw Mediawiki text?

Thanks, Travis