Firing from the shoulder using the GI sling swivels rotates the sight to the off side under tension. With paracord or a ring in the FSB it pulls to the side and there is only lateral stress. GI sling swivel locations were intended for carry and parade, not actual shooting.
The heat necessary to melt paracord involves mag dumping more than one or two - ROE is usually single fire or burst only thru the years, not full auto. If you are dumping mags then the sling attachment is very low priority and you likely won't survive long running out of ammo. It's a Die In Place effort.
Therefore - as veterans of actual combat use showed, the attachment to the side of the FSB was preferred. On the other hand, when Army finally woke up, slings were taken off in the field. That was the doctrine in the 80's and common throughout the 90's. Sling = cape, you will get messed up having one during operations in the field. No Sling.
This is why the FSB/paracord deal was actually shortlived. Works fine on a hunting AR but not so much in training and combat. Despite the tactical sling operators union saying they are mandatory. Nope, not so much. Slings are a LIC item for troops patrolling streets and patting down detainees, not so much for ops with a high chance of engagement.