But surely it is simple. If it is rendered in Bryce its a Bryce scene - if its rendered in DAZ its a DAZ scene (the finished look of these two is totally different) You have to remember that Bryce and DAZ Studio are owned by the same people and they are made to work together so I don't think you can penalise someone because they pose in DAZ Studio and then import it into Bryce.

Personally I think you are wrong to decide that anyone will make a decision on what is and what isn't a Bryce scene.