Yea if you right click on the dimension and go to properties for the dimension, there's a page called Secondary Units where you have the options to add another unit and how you want it displayed.
You could display the secondary dimensions and you could create a new template containing the two dimensions, so that you get them with every new dimention.
I think the limiting factor is Tolerance. You can only display tolerance values in the main units. The alternate units can only display a nominal value.
Pretty sure tolerances display the same value as the primary but converted into the secondary units.