Can an AkSpatialAudioVolume be concave?

Question

It's possible to reshape AkSpatialAudioVolumes into custom shapes, however in the Spatial Audio Blueprint Component documentation on the Ak website, there is a note vaguely saying they should be convex for accurate portal room intersection:

Automatic assignment of rooms to portals only works for convex meshes. Concave meshes (e.g. L-shaped rooms) do not produce accurate portal room intersection. 

Can someone elaborate on this? Are there scenarios where rooms can be concave, and what are the limitations? How would we go about adding different Volumes to a series of tight concave rooms?

Thanks!