Weld subframe connectors loaded or unloaded?

To me the best way to weld them in, is have the car on jack stands under the frame, we use eight jack stands. Shim as needed. Check to see if the car is level all the way around and your doors shut easy. If the car has any twist in it. Your car will always be that way if you weld them in without doing this. Unibody cars will always flex. That why frameties are used.