I had several FNSs. I remember being pretty impressed with the engineering. I don’t know if I wacked them before I sold them though.
As I recall, the system was pretty Glock like. Don’t remember if the sear interface was fully supported or not.
Triggers were meh, but barrels were very good and accuracy and reliability high. I liked them but did not feel FN really cared much about the consumer market. After the FN drama thread I got out of them.