I assume the anchor nodes take their time via NTP and a general NTP pool?

Have there been studies of time drift on anchors?

Is there a way to configure a specific set of NTP sources?

AFIK, the only RIPE article on this is this blog: https://labs.ripe.net/author/philip_homburg/ntp-measurements-with-ripe-atlas... At the time, archors did use the pool. But again, it is from 10 years ago. /giovane