Can assets in a tree have additional properties associated with them?

[Ben Hines]

I'm adding assets to a tree using the spy.assets.Tree.insert method and passing  a dataframe with columns "Name", "Type", and "Path".  This works perfectly and I can build/update the tree nicely.  I added some columns to the dataframe thinking that these would become visible as properites in the info view for each asset in Workbench.  However, I'm not seeing these.  Do assets not support additional properties?