Parametric cells are only placed on active level, compared to Graphic cells where the levels are independent. This limits creation of 2D parametric cells where many levels are included with the cell since the active level that the parametric cell placed on controls the display other than the levels that the elements within the parametric cell drawn.
If parametric cell levels are changed to be independent, it can be used to create more 2D cells with the parametric capabilities.
Moving to MicroStation Ideas