I believe one of my local forum mates handles more than five accounts but he is smarter than a fox. He uses different exchanges to send his signature payments. When he applies for campaigns, he does not submit his address first. He edits his application later and adds his Bitcoin address. Now, could you think why he did not post his Bitcoin address in the first place? why did he edit his post a five minute later and add his Bitcoin address?
I always assumed it was so they wouldn't make mistakes
like this, but now that you mention it, yeah that does sound like a crafty way to avoid the address from being scraped.
This, indeed, is a crazy effort to get away with, and maybe rules could be made. This would point to a rule in signature campaigns that there are no more "reserved posts" or incomplete applications at the start of posting in the signature campaign thread. Maybe a small thing to prevent cheating.