Would you be able to clarify what you mean? Are you talking about a WBBB-style footbox on a gathered-end hammock? Or.... did you mean footboxes (feetbox?) on both sides of a TQ?
If you're talking about the former, you'd only need two. (Flip the hammock over and it's automatically four.) I don't know why that wouldn't work- but what are you trying to accomplish? Sometimes, if "the community" knows what it is you want to get done, they'll suggest something that hadn't crossed your mind yet.