KingSpec M.2 SATA 2242 SSD Internal Solid State Drive 2TB ROM High-Performance Hard Drives Computer Disk Data Storage NAND Flash PC Desktop Laptop Upgrade for White-Collar Game-Player - Newegg.com
M.2 2242 SSD 2TB Dogfish 3D NAND QLC SATA III 6 Gb/s, Internal Solid State Drive Compatible with Desktop PC Laptop (M.2 2242 2TB) Internal SSDs - Newegg.com
Amazon.com: SSD SATA M.2 2242 2TB Dogfish Ngff Internal Solid State Drive High Performance Hard Drive for Desktop Laptop SATA III 6Gb/s Includes SSD 60GB 120GB 240GB 250GB 480GB 500GB 1TB SSD
Well I did it, I managed to stick a 2TB NVMe 2242 drive ($120 used) into my Steam Deck 64GB! With a little bit of modding, pls don't try at home :)