Tubular upper a-arms - Should I be worried?

Moving 1/8" because of weld cooling is totally bogus. I would ask for another arm...ask them for the dimension it should be...then compare to yours. Have them replace the one that doesnt match the dimension they give(assuming one of them does). There is hardly any welding in a control arm. I have done literally 10+ feet of continuous welding, and would have less than 1/8" of movement from weld cooling.
I cant say how good they are, but that would make me feel skeptical about them. Honestly, I am not sure is 1/8"(how accurate is this dimension??), would cause any issues. Its one of those situations where it may not cause issues but you know isnt "right". Just my opinion...