Add all available parent values to Insert drop down?

I know a lot of these parent values such as Length, Width, Depth, and measurements are available to use in the child formulas but I'm not sure what all is available. Could any available values be listed in the "Insert" drop down? Maybe add "Parent >" below "Volume >" and list anything else that we can use in the child formula? By the way, the way you have volume in CY, CF, and CI is awesome. That makes putting in a formula to calculate how many 2.25"x4"x8" brick it takes to build a 2'x2'x6' column so much simpler.