Running minimal preload allows the spring to unseat, and knock around/ make noise which is likely what's happening. Also worth noting it looks like Eibach is doing a sale next week.
The noise came from a combination of clearance tolerances between Ford and Eibach which was not found on Eibach's test vehicle, not an improperly designed part. They are safe to drive on and do all of the same things the first version did so if no noise, no concern. I would suggest reaching...
well that would fully explain the situation with the exploding bump stops as well. If the spring perch is different location than what it is supposed to be, then you will have less travel before hitting bump stop, thus, making it the weakest link before splitting. What trim level are you?