Weld subframe connectors loaded or unloaded?

I did mine on cribbing under the tires and left the /6 and trans in the car. I felt it was important to keep the car loaded like it is when rolling down the road and "fix" it in that state. But it's just my opinion and the only car I have done it to so take it with a grain of salt.

I know of one car that had a bunch of chassis stiffening done to it on a lift and they struggled to get the panel alignments done after that. I think they bowed the chassis while on the lift and then welded it solid in that shape. But again, just my opinion.

I suppose if you could figure out if the chassis is bowed due to hard use, maybe you could bring it back into shape and then add the connectors, but not really sure how to figure that out. Maybe get the doors aligned and then put it on jack stands with the suspension unloaded and see if the alignment goes out?