>>106487438
the usb 4.0 / usb 20g external nvme enclosures can get good speeds for file transfers. I've never tried mine for playing games.
option 2) get one of those x8 pcie bifurcation cards that let your run 2 more nvme drives, or get the x16 one?

finally, the low hanging fruit is to just get bigger ssds. 256 GB ssds are from 2013; 512 GB 2015; 1 TB 2019; 2TB 2021; We are on 4TB drives now.