I have been running RDS on Windows 2012 R2 since it came out, it works fine. Citrix is a smoother ride I am guessing, but RDS works for the legacy apps we use and RDS desktops. You manage the solution via the Server Manager, not sure if it is supported via the new web manager. It was a fairly...
One can check if this ticks enough boxes. Management for xcp-ng.
Better then KVM? I like and use KVM in production, but this is on the table as a possible replacement when the time comes for a refurb. XCP works great in my Nuc lab.