Buying a Stubben Diana--- Experience with the "girthing system?"

I am in the process of purchasing a Stubben Diana, and it has the original birthing system. I know these are pretty rare, but I’d love some opinions. Do they pinch? Are they durable/reliable? Do they keep the saddle secure enough? Hard to use? Will they be okay with a breastplate attached? Thank you for any help at all!

I had an old Diana but before i bought it, it had been altered to have long billets so it was just like any other monoflap. Ive seen pictures of the original girthing design but havnt used it personally. But if you dont like it, it clearly IS possible to put regular billets on it.
Loved that saddle though! An oldie but a goodie.