As far as DOT certifications are concerned, if the belts don't specify on their labels that they have DOT certification (along with the appropriate DOT code numbers), then they aren't. It's not likely that any motor vehicle inspector is going to allow non-DOT certified belts for use on a street vehicle, regardless of any overkill factor.
I'll be getting a 6-point set for my car, with removable clip attachments, for track use. But for street use, I'll be putting in removable DOT-certified lap-and-harness 3-point belts. The cost of a ticket (here, anyway) for non-compliant belts is as much as an SFI belt, so this all makes sense. Plus, you can reach all your controls, adjust your mirrors, etc. without unbuckling. And, it wouldn't be likely you'd get the car successfully certified as road legal without them in the first place...at least not here.
Your results may vary. Close cover before striking.