Until https://issues.redhat.com/browse/FDP-162 is implemented and delivered to OVN and OVN-K, we have to allocate /64 prefix per OCP worker. This implies changes to the network setup. This limitation should be documented, and a general guidance on how to proceed with migration should be provided.

(The guidance would be - to allocate a wider prefix for OSP Control Plane.)

Note: this limitation applies to adoption as well as greenfield setups, and should be captured for both scenarios.