If you are experiencing periodic freezes of the game (no sound, no animations, but the mouse cursor still works), you can unstick by the game simply by hitting alt-tab or focusing another window and back.
The problem looks a lot like a concurrency issue with the PhysicsFS library used in many games, one that used to make the Stellaris loading times so horrendous, including that it coincides with a huge spike in disk IOPS vs disk throughput, but in the BG3 case you can break the deadlock simply by alt-tabbing or injecting a WM_FOCUS into the message pump.
