I have a small problem with a WWTP; It was designed with collisions in the folds. When I import it there are errors due to collisions but when I want to remove material to remove collisions it doesn't work and if I convert to sheet metal it 's the same, it doesn't work. Maybe something very simple that I haven't thought of! By dint of having our head in the handlebars we no longer see the simple things ....
The only solution I can see to correct these problems is to use the surface to shift the surfaces by a few tenths. But I think that going through this means would take more time than redoing the whole piece.
I understand, it was hard for me to choose because I still had to redesign the part because during your conversion it has the thickness that jumped and a crease (from 2mm to 1mm) and if I change the thickness to go back to 2mm the part no longer unfolds. Given that mgauroy had said that it was easier to redo the part in 1st my choice was inclined to his answer.