Technically, anti-cheat requires control over the system (computer being used, room and network where the test happens). An open source operating system could

Technically, anti-cheat requires control over the system (computer being used, room and network where the test happens). An open source operating system could be used to block or circumvent the control check points of said spyware. So installing it on your Linux workstation may not provide enough guarantees. But... the unasked question, but important one is: why install one on _your_ computer? If someone (school, org, whatever) needs you to pass a test, they can provide the whole package if they want to exert control over the whole context of the test. But submitting in advance to their own requirement (it's not _your_ requirement), by compromising your own computer? This may as well be a hidden purpose test, where refusing to install said software is the "good" answer. And if the employer doesn't accept/understand that, that's... problematic for them on a whole other level.