A rift in the NTP world
Why not get rid of NTP altogether?  For servers, they ought to be able to accept a hardware time and frequency inputs.  Typically this would mean a 1 Pulse-Per-Second (PPS) signal and a 10 MHz signal.    You might also want some kind of serial signal that describes the date and time to label the last second pulse.Why don't any professional servers come with this kind of connection built-in?  Why can't I synchronize my Xeon chip's clock to my own reference frequency?