I'm assuming that when I reject a [spam] registration from the Admin CP, that user is not reported to the spam services the same way as the Spam Control function? Shouldn't there be a fourth option called Spam that takes care of this?
Just to clarify, are you seeing actual evidence of the users spamming? (Via the profile I'd guess.) Using StopForumSpam as an example, the terms state that you can't submit users to them unless they have actually spammed. Thus, someone solely tripping the thresholds for manual approval, based on data in their service, should not be submitted to them.
Yes every single one has a spam link in the profile, along with other obviously incorrect info in the profile. I don't see this being abused anymore than a mod/admin abusing the spam cleaner function.
Thankfully the XF spam features have become very robust. Very seldom does a spammer get through the registration process to the Awaiting Approval step, much less a live thread on the site. IP banning half of Pakistan cut it down about 75% as well.