I think that’s a fundamental problem: A tool like faceit takes freedom from the user away. If it was open source (i.e. modifiable), it could lie in favour of its owner. Since Linux is open source, a good programmer could probably get Linux to lie to the tool to send the wrong data and therefore allow cheating. Controlling the user requires a system the user has no control over :-)
Sounds like “screen”? (I never heard about tmux until today, I work a lot with Linux on a daily base, maintaining servers etc. I use screen a lot.)