Had just attempted Death Rays of Sunshine. We had superman up and 3 repaired machines for a total of 4mins:30s. We started the timer upon the 3rd repair of the machine. We waited, survived etc and then completed the requirements of the feat. It did not give us the feat. Have proof should it be required.
Hey we might’ve been in that raid together as I ran into the exact same issue. Just ran it today but instead of destroying 3 and letting her repair them, we simply kept the originals all up and prevented her from fixing any at all. When the timer was over 4 minutes, and we finished the bosses, the feat popped. Not sure if both ways are supposed to work but at least this method does work so the feat can be unlocked still.