First, a question about your last sentence. What’s your definition of a “normal builder”? Didn’t know there was any such animal

Yep, the depressions bother some people.
I used a piece of .035 wall square tube and did some testing to see first-hand what a depression looked like.
https://picasaweb.google.com/tonyboytoo ... 1682927730
https://picasaweb.google.com/tonyboytoo ... 4545013122
https://picasaweb.google.com/tonyboytoo ... 3618957538
Based on that, I elected to go with protruding head rivets in the cage. The very last rivet was pulled about two hours ago.
Tony