I'm not sure... The YouTube video that mention about a enclosure that works is this: https://youtu.be/6eqi5TrN7jM?t=415 and that ASUS enclosure is too expensive to make it worth. I'm now tracking this PCIe adapter to do the firmware upgrade (https://smile.amazon.com/dp/B074ZV31CF). What a waste of extra work that Samsung have us do! If I knew this earlier, I'd not have bought 980 Pro.
It'll drop your GTX 970 to PCIe 3.0 x8 but that's still plenty. As for the adapter, I have no idea. Check <strong>Amazon</strong> or <strong>eBay</strong> for cheap solutions. Anything that accepts NVME drives with PCIe 3.0 x4 slot.