As I saw the locations of these barriers last year, I would say that the parking lot in Zadnjica is outside the barriers.
The turnoff towards the Soča spring and Flora, I think is still before you reach the exit barriers on the Primorska side... so according to my logic, for the Soča spring they will treat you the same as if you park at the top of Vršič. I would also say that the same applies to the Russian Cross
But it's just weird how this will work with the counting of limited parking spaces on Vršič where they are supposed to block the entry barrier for parking when too many cars are already parked at the top of Vršič... What if you don't intend to park on Vršič at all and want to go to Flora? They will then prevent you from parking at Flora because there are too many cars at the top of Vršič
But please, can someone correct me if I misinterpreted what they intend to do with the other parking lots that are not at the top of Vršič.