We have plenty of licensed RHEL, but in isolated environments the hurdle of connecting to a Satellite server or their subscription hub on the internet is too high -- at least with Rocky and the ilk available. For this set up, the licensing model doesn't match reality, at least not easily.

Are we really going to build out compatible configuration management, monitoring, logging, etc? -- it's not a seamless transition. How much time do we have to put towards this?

And yes -- there is software compatibility issues. Look at the OpenHPC software distribution, it's designed for SUSE or Enterprise Linux: https://github.com/openhpc/ohpc/wiki/2.X