i believe the latest rumors suggest 16GB unified GDDR6, but the relevant tech here might be sophisticated caching technology that also leverages a fast PCIe 4.0 SSD
So presumably, the engine now does that kind of stuff at load-time. The bottleneck is then the place on the SSD and the scene change pace. This fits quite nicely with the repetitive statures, but it leaves a question mark for that final flight.