I guess it depends on how far out you are doing the drop and how much you drive it in the meantime. The angle might not be optimum, but it's not like you track the car either, so I don't think using the higher hole would hurt anything. I've pondered getting even a socket on the bolt while mounted in the car, I can't see it. If you can't get it tight once it's in the car, you will have a problem.
^^^+1. You have to torque the forward UCA/mount bolt properly before installing the mount on the car. You won't be able to get a socket with torque wrench on either side with the mount installed.