VrayToon

[gfa2]

It would be nice to be able to add groups and/or layers to the include/exclude list of VrayToon.

[DanielBrew]

+1 for layers.

[m_hinks]

+1 and even better for me would be xref scenes!?

[tashko.zashev]

It would be nice to be able to add groups and/or layers to the include/exclude list of VrayToon.

There is possibility to add layers or objects groups, just follow the steps:
For layers : open V-Ray toon parameters > click on Add> choose "Select objects in current layer" > open 3ds max selector "Select by name" and click OK.
For groups : open V-Ray toon parameters > click on Add> open 3ds max selector "Select by name" > choose your group and hit "Pick"

+1 and even better for me would be xref scenes!?

Don't think that this is possible because XRef scenes cannot be selected nor modified, and do not appear in the Select From Scene dialog or Scene Explorer, the modifier stack, or the Track View.