To clarify. In V-Ray 7 GPU MultiMatte render elements will not show Forest objects, if they are part of the include/exclude list of the element.
This is not a psd-manager issue. There is no involvement of psd-manager itself, other then that it can export this V-ray produced image data.
If possible please change title so others find it: V-Ray 7 GPU, MultiMatte elements ignore Forest objects in include list.
Workaround 1: assign an Object-ID to Forest objects and enter ID in MultiMatte
Workaround 2: use V-Ray 7 CPU or V-Ray 6 CPU/GPU to render
Status: Bug has been reported in detail to Chaos with sample scene, screenshots, affected versions etc.
Daniel Schmidt - psd-manager Developer