If they don’t have two graphic card slots ofc you wouldn’t use that, I mentioned it because my mono has two. I’d be surprised if their PC only had two SATA/m2 slots overall though. If they do, they sadly are hardware bound, maybe they could buy a USB to m2 adapter (like a big USB case) and use the M2 like an external hard drive, but that only works well if the USB slot is 3.1 or 3.2, I don’t remember which.

All I’m saying is that getting a add for games like PoE, helldivers and keeping Stardiew valley on the HDD, or just keeping the current active games on the SSD (I did this since forever when I had a 500gb SSD and a 4tb drive bought 8 years ago) should improve their experience a lot.