Creating dummy displayable and display nodes to show color legend

I’m trying to rework Isodose module, so that color legend was used instead of scalar bars.
There is a IsodoseNode that is used as parameters storing node.

I want convert that vtkMRMLNode to vtkMRMLDisplayableNode and also add vtkMRMLIsodoseDiplayNode to store isolevels color table node. In that case IsodoseNode will display color legend and nothing else.

Are there any drawbacks of such scheme?