What's the functional difference between doing that and simply using them one at a time over two actions? Just the combined attack roll? I guess that doesn't break anything, though it's not the intended usage.
When you put it like that I suppose its really just flavor, though in some cases combined damage types could be significant for avoiding single type SOAK. Based on your earlier post in this thread though it would be impossible to use them one at a time over two actions since you can only uses exploits once a turn and both of them count as exploits so after the first action you couldn't use the other one.