Yeah, the flat flange will seal better than that raised edge. So that doesn't bother me.
The only header I know that has a welded ring is Hooker. Everything else is loose. Except maybe TTI.
And that doesn't bother me either.
What bothers me is those headers look like they were installed, several times and then sent back.
That's would piss me off. There is no way I'd have accepted that either. Summit or Jegs or whoever sent those out ought to be ashamed.