Sub-frame connectors... Please build them correctly!

I was speaking with a near neighbor down my street - he has a bit of a shop built in his backyard for his part-time after work job. He welded up my K-member for me and I then asked him about installing some welding in SFC. Mentioning that I would want the weight off the car on all four wheels he said what he would do is get under the initially and tack them in place, then put it on a lift (not the drive on type) and then finish the welds in a more convenient position.

Is this a reasonable approach?