Hey Bruce, I sent some emails inquiring, but any help would be appreciated. I truly believe this is within the spirit of the rules, there is no torsional rigidity gained from these small diameter, un triangulated bars. Rather, this is about safety; I would much rather have my butt tied to a DOM spaceframe than some .060" sheetmetal that was spot welded 20 years ago.
Since I made that post this morning I am finding MANY GTS guys that do the same thing, the more racers I find with seat mounts connected to the cage, the more it makes me think that it is common practice and I am just spending too much time with the BMWCCA guys, haha!
Regards, Nate.