Gnarbox 2.0 SSD upgrade

It says it uses NVMe SSDs, so in theory it should be possible. This will void the warranty if you have one that’s active and it may impact the water resistance of the drive.

If you’re okay with risking the water resistance and loss of warranty, it may very well be possible to replace the drive(s) installed. Get a good one like the WD Black NVMe series and you’ll be okay. If you bought the 256GB one, it may not be as easy with the entry level version (256GB) based on the FCC teardown. The 256GB version uses a M.2 2230 drive, which may make it a bit more difficult to get a drive easily as it tends to be an “OEM only" size with most vendors, and will likely be for a while although that is changing as of 2022, somewhat. The drives are still often “OEM” (and have no warranty) but you can at least buy them now. The situation has gotten better in recent years but it's still a potential problem where you may be limited to OEM parts or Chinese SSDs based on a reference design. Hopefully the 512GB/1TB versions are more practical to upgrade like you want to do.