Big hitches removing portal components

Question

Hi,

We are using WWise 2021.1.4.7707 in UE 4.27.1.
We have a big seamless world in our game and and we are using streaming levels to load all audio-related actors.
We usually have less than 20 rooms and 40 portals at the same time.

We are having big hitches (25-100 ms) in the game thread when the portal components are removed from the scene (UnregisterComponent).
We checked the implementation and it seems that all the rooms of the world are updated when any portal is removed from the scene (UpdateAllSpatialAudioRooms).
1. Is this behaviour intended? We think that the audio engine should only update the rooms that are intersecting with the removed portal, are we right?
2. If this behaviour is intended, what can we do to reduce the time when removing portals? Do you have a guide for designers with information about best practices designing rooms and portals?

Our audio designers are usually creating simple convex rooms (less than 20 faces), but they create concave rooms sometimes (less than 20 faces).
3. Do you recommend us to stop using concave rooms?

WWise is also displaying the following warning sometimes when adding new portals to the scene:
[2021.11.24-10.36.17:986][805]LogAkAudio: Warning: UAkPortalComponent ManseCBridge3_Portal2 must have a front room which is distinct from its back room.
We think that this happens because sometimes the portals are added to the scene before all the intersecting rooms have been added to the scene.
4. Should we always put all the rooms and the portals that use these rooms in the same sublevel?

Thanks in advance for your answers.

Best regards,

Sergi