Same problem here, most areas are affected, but moreso on the larger areas. The zone can be empty but still exhibit the behaviour.
One area that can easily replicate it is by going to Hinterlands just south of Idyllshire and point the camera towards the Alexander bubble and start spinning the camera it will stutter when pointing towards alexander, but will be 60fps the rest of the time. The PS5 beta client will stutter regardless of the resolution mode. 1080p, 1440p don't really make much difference, 4k fps is very low, unstable 30-40fps probably. PS4 client (running on PS5) runs smoothly in those areas in 1080p and 1440p modes, only time the PS4 client drops frames is when there are a high number of people like are around quest NPCs or in hub cities, and even then it isn't nearly as much as the PS5.

So there are clearly some performance issues that need to be worked out!