You can try to justify the Thai way but the welding shown on the roof is not characteristic of their ability. The paint says they are finished welding. Yes they do spot welding but normally it will be 2 inch spots rather than running a continuous bead, thus saving rod and time. The overall spot weld is normally about one half of the potential weld. Maybe semi spot is better term and this is accepted and does provide enough strength. The obvious gaps are probably due to the position/height of the support bean on the support column being somewhat off. I have built 2 houses for family and 2 for friends here and the steel roof was always installed/welded by crews who only do this work for various contractors, same with the installation of tiles (C-pak) a contractor who uses the same crew is expecting more from his workers in the way of versatility than any I have observed.
Tell the wife to watch when they wire tie the C-Pak on roof iron, they will try to tie one in four is your lucky. Now I just have them tie every tile down and put access to attic thru ceiling in convient place in the house. good luck