If & when this MacMini an no longer take any more updates in its' present MacOS, since it is as far as it can go, and I try going back to Linux (Will use Mint, up to Mint 21 now), instead of using my DVD/CD Rom USB drive, been awhile, I'll get a USB (SSD) stick, at least 4G is recommended.

Now it gives you an IOS image I read, Is it a PIA to convert it to whatever is needed??? Too long ago, I can not recall :-)