(I guess the article is in German, but google translate did a good job on it) This relates to the desire to amend RFC7084 to support "southbound" DHCPv6-PD: https://datatracker.ietf.org/doc/draft-winters-v6ops-cpe-lan-pd/
https://www.heise.de/select/ct/2023/2/2230709000622055021
Alexander Traud tested 29 CPEs and tried to understand how they react to prefix changes.
Router cascade with DHCPv6-PD With routers connected in a cascade, the internal network can be divided into several zones. This is useful, for example, in shared apartments that want to share an Internet connection, but each resident should still have their own (W)LAN. To do this, the front router, which is directly connected to the Internet, must pass on part of the prefix it received from the provider (DHCPv6-PD, prefix delegation) and its DHCPv6 server must ideally be able to use DHCPv6 reconfigure. Only AVM and Wavlink offered both in the test field. -- Michael Richardson <mcr+IETF@sandelman.ca> . o O ( IPv6 IøT consulting ) Sandelman Software Works Inc, Ottawa and Worldwide