In the truest terms, a 2/32″ tread depth difference would exceed the 1/4″ rolling diameter test.
That said, if you had to…. I would put the two with the deeper tread in the front. Typically most FWD / AWD vehicles tend to wear the fronts a bit faster than the rears. I won’t be all that long before you are nearing specification.
I’ve heard of folks mounting the deeper tread tires up front and doing a quick one time burnout to kill off a fraction! I’ve also heard of decreasing the typical Subaru 1 lbs air pressure differential front to rear (fronts typically have an extra lbs to compensate for the added weight up front to keep rolling diameter equal front to rear) to dead even. Dropping that differential to zero allows the fronts to compress ever so slightly.
