Hi Ken-vdE
I finally had some time to review your analysis and I cannot agree more. What you describe in point 5 is exactly what I have experienced with the position attribute.
So far I have "solved" it (or better said, handled) dragging manually Attributes and Values after importing them. This has the disadvantage that, as you said, if you delete all combinations before importing, everything gets mixed up again (as recently happened to me).
The dummy product with all the possible values and combinations is a good idea that I also came up with, but right now I have 36 different Attributes and some of them with more than 100 values (many depths, heights and lengths). It is a work to have it done and keep it updated. But considering the work it takes to rearrange all this... I think it's worth it. I will have a look to your CSV and think about how to configure my dummy product. EDIT: I guess I can download the current Attributes and Values list from my shops's database itself and work out a CSV file from there. At least I will have the current values arranged for the next "general import".
Thanks a lot for your analysis! I think that Prestashop still have some work ahead regarding imports, as for example, an option for importing shipping costs!
Best regards,