Quote - Whatever I do, I get a ignore message in the Log for each of the parameters aconst to econst. But the parameters are definitively used.

Yes, as I said several pages ago, don't heed the Lux messages. Those parameters are used, they define the sky colors. If you omit them you get a white sky.
Somebody please add it to the knowledge base, as it is a recurring topic (4th or 5th time I see it). IIRC I had already mentioned it when I first posted the sunsky setting, many weeks ago...