I know, dead horse, but the anti-sub strap is rather important on race belts. It must be directly behind or below the buckle because otherwise it, literally, does nothing. I've seen so many badly installed anti-sub straps that I'm not sure people are really aware what submarining is/how dangerous it is. Unless the harness is designed to be a 4 point, it's not going to work without a substrap. Cheap/Knock off belts aren't worth your life.
https://youtu.be/HR_FhuSEaU8
https://www.24hoursoflemons.com/images/How-Not-To-Fail-LeMons-Tech.pdf
Customer is having the stock seat modified for a proper sub belt mounting.
Sorry Keith, I should have been more clear; that response was only tangentially (spl?) related to your original post (i.e. I wasn't trying to harp/preach at you, just the dead horse of 5/6 point sub straps in a general sense). That was more a general pile of information. I have a fear of people googling for this type of question, and coming to odd conclusions after digging through this thread (internet "old wives tales").
Like I said; I've seen a lot of 4 point harness that shouldn't be, and 5/6 point straps mounted where they wouldn't do their job as well as they should.