Sure. Set your document properties to whichever you have more of. Then the ones you want to change, select and then in the PM, override the units.
I have our drawing templates set to Ft-In and 32nds but not round to some fraction. I don't like stupid rounded off fractions because you don't know what the number really is. Then the drawing will display fractions for dims that are an even fraction of at least to a 32nd, and decimal for the ones that are not an even fraction. Then I make a decision as to how I want to handle each decimal one. I may go back to the model and make a change to make it an even fraction, I may force it to round, or I may leave it decimal. My choice.