You'll be fine. I wouldn't bother with the Asus hyper card though. I've used probably about 60 of these now with Samsung NVMe SSDs: https://www.amazon.com/gp/product/B00MYCQP38/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
I did just this on an X370 board who's 2nd m.2 connector is PCIe 2.0 x4. Naturally it limited the sequential performance of the SSD to the slot's bandwidth (roughly 2000MB/s) but the IOPS still met the spec of the drive, which in the real world is what's actually important for performance on these SSDs. Note that Samsung magician may not recognize the SSD as "genuine" and won't be able to update its firmware. Your mileage may vary however. That happened with mine but I'm also on a brand new Ryzen platform with pretty fresh BIOS revisions so it could just be that for me.