
I found a cheap SSD 'MS950' equipped with YMTC's NAND that is compatible with PCIe Gen 4 but costs 17,980 yen for 2TB, so I actually bought it and checked the transfer,

Nextorage Japan 4TB NVMe M.2 2280 PCIe Gen.4 Internal SSD - New G-Series | Read Speed: up to 7300MB/s | Write Speed: Up to 6900 MB/s - ,

WD 4TB PCIe Gen 4 x4 NVMe 3D NAND M.2 Internal SSD w/ Heatsink - Playstation 5 Compatible - Micro Center,

Crucial T700 4TB Gen5 NVMe M.2 SSD - Up to 12,400 MB/s - DirectStorage Enabled - CT4000T700SSD3 - Gaming, Photography, Video Editing & Design - ,

Crucial T700 4TB Gen5 NVMe M.2 SSD - Up to 12,400 MB/s - DirectStorage Enabled - CT4000T700SSD3 - Gaming, Photography, Video Editing & Design -