Shoulder harness bar?

I have a problem that I think I have solved, but need advice form those in the know. I am looking to add a bar for mounting the shoulder harness. this is part of a 6 point harness. I have the Racetech seats that were originally designed for the Saker car.
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They fit nicely in that they are semi recliner and match the angle of the rear bulkhead.
My first choice for locating the harness was through the bulkhead just under the window. The DRBs have this as an integral part of the frame members and is thick.

I drilled holes for a bolt mounted system. The anchors were bent at 90º as shown in all the instructions for the various belt manufacturers. The 3 bar anchor that ties the belt to the bolted anchor winds up hitting the back of the seat. This is disallowed in all the instructions. The angle is less than the 20º allowed.
I didn't want to move the seat up enough to allow this option. I consulted Shepard Racing, the group that did my headers and they felt a bar behind the seat, connecting the cage, would be very difficult to place due to its closeness to the bulkhead. We looked up the rules for the shoulder harness bar(SCCA) and found that it can be a lateral bar connected to the cage, or to a structural member of the car frame. I have looked it up again at home and can't seem to find the exact wording. So I am asking those of you in the know what is allowed. I would like to use the frame member for its simplicity of installation. What are the thoughts out there? I have never seen one mounted this way, but then I haven't read the rules before today.