You can't see it in the picture, but he welded the seam that goes down the middle on the bottom. It's already at the paint shop, so that is going to have to be enough. The lower control arms have stiffening plates welded in already.
It should be fine, all of the force seems to be on the LCA bushing and strut bar area and not as torsional side to side in nature as it is in up and down twisting. I'd like to think that the edge welding is overkill anyway.
Who's ever seen the bottom come off of a K member due to corner carving or big power?