If you ever wanted to have Maya’s MASH to drive custom attributes, there is a node for that. The Breakout node, or Breakout Utility was created just for that purpose. MASH Breakout lets you drive any animatable attributes using MASH networks.
Johan Borgström shows how he is using the breakout node to drive custom attributes, using a script he created that automates some of the connections. Before the breakout utility, you were destined to create your own driver using expressions or a scripting language.
Johan’s MASH breakout node Connection script looks pretty handy. Keep in mind that driving attributes with MASH is something that you can’t do on your own, the script he is using in the demonstration only makes it easier.