What I’m saying is that if you are enabling unvetted users to run things on your hardware, for free, you probably shouldn’t be doing it on consumer hardware in the first place.
If the users are paying, doubly so.
If the users are vetted but free, then this is a “your friends are hacking you” problem.
There is nothing wrong with using consumer hardware to host servers. I’m doing it right this moment with great success. What I’m saying is that if you have public gitlab runners, then you’re just hosting a Monero mining rig for randoms in the first place.