Scotty, The TIG rule is in the General Regulations and is in effect for all CM roll bars and cages, even those slow enough to not require certification. I have zero experience with CM and have no opinion about what effective welding practices are. I'm just giving my interpretation of the rulebook. Personally, if I could build a CM chassis/rollcage HA/GR, I would. But, I'm stuck with my heavy MS HA/GRa. It will probably go on a diet next year.