Most of my work involves modeling both existing and new equipment. Currently, the only way I know to make new parts show up as bolder is to set up a new layer and manually change each individual line to the appropriate new layer - this is very time consuming and frustrating because I have to consider visible and hidden lintypes separately.
It would be great if I could select whole parts (i.e. "Select Part Priority" instead of "Select Edge Priority") that are new and put them on a new "part layer" to distinguish them from the existing components. The Part Layers would be groups of layers consisting of all of the standard linetypes (Visible, Thin, Hidden, Hatch, etc), so If I place a part on a different "Part Layer", the visible and hidden lines would both turn into the lineweights as defined within the user's custom part layers.
For example,
Part Layer - "Existing"
*Visible = 0.005
*Thin = 0.003
*Hidden = 0.003
Part Layer - "New"
*Visible = 0.0125
*Thin=0.010
*Hidden = 0.008
Other uses for part layers would be for me to call out Demolition parts.