After printing some large parts in ABS (heatbed@95°C), it seemed to me that the fan ducts had come closer to the heating bed. Too close.
That's why I changed two angles in the model.
Afterwards I had the impression that it would have been enough to tighten two screws more tightly.....which had loosened in the course of time.
Nevertheless, I think the new design is an improvement. And that's why I want to publish it as well.