I've asked on the FAI mailing list about the usage of ISC dhcp and got a few answers:
https://lists.uni-koeln.de/pipermail/linux-fai/2025-May/thread.html Only one started the very slow the migration to dnsmasq. Most are afraid of the complexity of KEA and still use ISC dhcp server. But they know that they have to migrate to another tool in the future. -- regards Thomas