PL zero 7 bar instruction shows that the safety leash should be connected to the rear outside bar line. Watched a PL setup video that shows them connecting the safety leash to one of the center front lines via 2 stainless rings. Is one method preferred over the other or is it more a matter how your PL zero 7 bar is equipped (with or without the center rings)?

the 07 bar is back line safety and previous bars are front line safety. some people prefer one over the other but both work just fine.