This post is somewhat old now but if anyone looking at this in the future, I was able to use the city sample small level almost straight out of the box in ue5.4 across ndisplay. All I did was disable all the MassAI components (which can maybe work if built with a server since nDisplay supports replication now and mass should work with replication) and disable streaming from within the world partition settings but not world partition as a whole. These keeps all the hlods in check and doesnt make the map a buggy mess like trying to convert it to non-WP. Maybe changes were made for world partition in ue5.4 but I didn’t see anything like that in the release notes so ymmv but should also work ue5.3 and below.