You’re aware that you can send whatever traffic you want over any port right? Using 123/udp for NTP is just convention. A light bulb that is updating its time over Tor is suspect. TP-Link would have their own infrastructure or use public pools to update the device’s time.
I’ve been using this to automatically skip ads on my Chromecasts (youtube ads and in video segments) for the past year.
https://github.com/gabe565/CastSponsorSkip
It’s literally sponsor block but for all of my Chromecasts