Having PSD as an additional export file format to choose from would be beneficial for those who are going to further edit their files in Affinity Photo.
Affinity Photo lets you save over the open file only if it’s in the PSD format. Otherwise you have to export as a tertiary file, which is not an elegant solution.
Yes, this one would be very helpful.
Of course, .tiff support is a fine workaround, but it is more difficult to manage and archive. On a .psd file you can keep your edits even after saving the file, ready be modified any time is needed. Also, it’s a more portable format and can be read more easily across different platforms (yeah, I know, Adobe power and all).
I know that probably most of DxO Photo Lab users do not edit their shots outside the program (well, this is a plus DxO count, of course), but there are situation where the use of an external program is impossibile to avoid.