For my opinion it is important that all network devices in the own administrative domain have the same time. Or lets says almost the same time. Therefore we are using DNS RPZ ( restricted policy zone or also known as DNS as a firewall )
With this feature in BIND we are rewriting all DNS queries for *.pool.ntp.org to our own ntp servers. We do this also for Microsoft’s time server ( almost all PC’s have Windows OS ), Apple, Google and Ubuntu time server.
Are there any other major frequently used DNS names for ntp server ? I do not care if an exotic OS is not caught.