I am currently running a custom loop in my Evolve Shift X. It is super cramped with no room for expansion and I am planning on buying a bigger case. Now I was thinking of building a dual system in one case since I want to upgrade a few things and I might as well use what I have now as a streaming PC. Which brings me to my question...

Has anyone build two systems that share the same cooling loop? I am thinking that as long as one computer controls the fan speed etc, it shouldn't be a problem since the temperature will level out across the systems. Sure, one system might end up heating up the other. But how is that different from my GPU heating up my CPU?

Does anyone have any examples/videos of this done? I haven't been able find any myself.. Is it a good/terrible idea?