What's the commercial usage limitation? Is that specifically for virtualization of OSX to prevent offering a "Mac On Demand" by not letting you run the OS itself?
Turns out it's two, not four VMs. From macOS Sierra's EULA[0]:
> (iii) to install, use and run up to two (2) additional copies or instances of the Apple Software
within virtual operating system environments on each Mac Computer you own or control that is
already running the Apple Software, for purposes of: (a) software development; (b) testing during
software development; (c) using macOS Server; or (d) personal, non-commercial use.
With c) you're allowed to run up to 2 copies. It doesn't really help you run a hundred containers on a powerful server... (Not that you easily legally could, as I guess the moat powerful Mac hw available is the Mac pro - not exactly great for rack deployment).
[ed: i guess you mean running os x server is an alternative to "non commercial use" - I agree with that reading. The option for nc use seems like a nod to not completely make experimentation and creative development/research entirely illegal.]
