Okay, I've got some clarification to share. This should be the same info that will be distributed to SCTA clubs and members. There are two main points of concern. First is that welded D rings have been shown to mechanically fail when used as a tether adjustment either in the cuff that goes around the arm or the length adjuster to the driver's belts. Second is that welded D rings are made of round steel wire and the round profile lacks "bite" to keep the tether from slipping out. Because of these two reasons, welded D rings are only acceptable as an attachment point if there are two rings being used.
Non-welded D rings (stamped) are made out of sheet presumably and have a square edge profile thus they "bite" into the tether much better and do not slip and also do not mechanically fail since they're made from one piece. It seems the DJ restraint that keeps getting pictured is okay to use as is BUT it's not a bad idea to have it updated to add in the 3 bar adjuster to lock down the tail of the tether.
The attached pic is a good example of what's not acceptable. The adjustment around the wrist is a slip tether through welded D rings and even though you can't really see it, I believe the adjustment for the belts attachment is also a slip tether through welded D rings. Double no go.