For example I don’t know if a cheap mini PC like the GMKtec G5 would be more likely to have firmware/driver related security flaws over a more standard PC like an older Dell Optiplex from Staples.
Maybe there is something else entirely I am overlooking. I’m not sure. Most of the complaints I’ve heard are in regards to mini PCs containing bloat and potentially malicious things installed.
There have been several cases of the default OS installation being infected with malware. I would recommend always wiping the drive and installing your own OS. Firmware is less likely to contain malware targeted at individuals (or anyone else that is irrelevant to APT’s), but it might be outdated and have unpatched vulnerabilities.