The easiest way is to append the “No Macroprudential policy regime” economy as a separate economy to the mod-file and then compare the welfare. Similar to the way Smets/Wouters have a flex-price economy in their model, see https://github.com/JohannesPfeifer/DSGE_mod/blob/master/Smets_Wouters_2007/Smets_Wouters_2007_45.mod