Bicycle pads and rotors don't wear in to the same extent or patterns as car or motorcycle rotors. You can safely just stuff a different wheel and rotor in there and carry on. Or at least you COULD if these were dual piston hydraulic units. Because you're running a mechanical caliper where the inside fixed pad fit is critical you'll likely need to take a minute and retune the inner pad seating with the wheel swap since it's highly unlikely that the rotor will be in exactly the same spot to that level of accuracy.