Galvalume Panels Damaged During Install

We are in the process of building a house with a guest house (cottage). The house has some unpainted standing seam over a porch and bump out, and the entire cottage roof is galvalume standing seam. Many of the panels have significant scraping, scratching and what I would call burnishing. Most of the panels that are damaged are in areas that the installers were clearly using to walk on repeatedly. I understand that standing seam roofs are difficult to install and it is impossible to avoid some minor cosmetic issues, but this seems excessive. Can anyone provide some feedback?

Almost none of what you see is dirt. The roof has been exposed to several hard rains, and any dirt leftover was washed away before taking pictures. The brown areas you are seeing in the 5th and 6th pictures are actually rust. Additionally, there were numerous panels with muddy footprints, and the dirt stayed on the roof for over a month. When I finally washed the dirt off, those areas were discolored, splotchy, and obviously scraped. If you're putting down one panel at a time, I don't understand how this extent of damage could be considered unavoidable. Is the finish on these panels so sensitive that it can't handle even light foot traffic during installation?