Check that your raw converter / editor can read Z6 iii raw files!
My Z6 iii NEF files can't be opened in DxO 5. (From online comments, it appears they won't have it ready until September, and it's likely that it will be available only in DxO 6, 7, and their new version 8 in Sept.) They say they need to finish their detailed camera profile.
The free darktable can't open them either. (It will probably never handle "high efficiency" raws, since these are a closed, proprietary format. darktable is open source, freely available.)
Adobe's free DNG converter did convert my NEF uncompressed files into DNG, and darktable could open them. DxO still refused to open the DNG. I'm not sure that the DNG converted raw has as much editability as the original NEF?