This is more a feature request, but maybe I overlooked something and may be wrong myself.
My RUT955 (RUT) is configured as a SNTP server, self syncing with built-in GPS receiver. I have a SNTP client, reading time from this RUT. I learned, that during RUT startup my client switched its clock to wrong time. Also, the web interface of RUT shows the same wrong time for a while after boot. This is corrected in about a minute, when GPS module gets synced with satellite time - both RUT and client reset clock to correct date&time then.
You can reproduce this behaviour easily. And if you boot RUT without GPS antenna, you will have wrong time NTP server (declaring stratum 1) forever.
I believe, that RUT implementation of SNTP server should refuse sync clients until it has good time from GPS.
I solved it with NMEA "GPGGA" messages UDP forwarding to my client IP address, so this client can wait until there is written good quality and number of satellites in message, so RUT SNTP server can be trusted. But some clients can't be programmed this way, usually you have just an option to configure the IP address of server and sync frequency.