Here’s some photos of the Hello World. I’m concerned about some of the joints.
Not enough ink? Not enough burnishing? Some joints filleted during reflow and look good, and on some the solder paste wicked up on the part and not much at all was on the pad.
Since some of the joints look ok, it must have gotten hot enough?
Also, I understand some of the nonplanar behavior is expected (LEDs topsy turvy).