When mounting a unc path in v13 (v12 is the same) on Windows 7 x64 (probably idependent of the Windows version), it is possible to use a server and a share when following these steps on the "Select Directory" dialogue:

Desktop -> Network -> choose a server -> chose the share -> choose the desired folder

But this only works if the server appears and if the share is not hidden

An alternative to this is to mount any directory, go to the .datastudio/filesystem subfolder, choose the file that has just been created and replace the directory by the unc path (don't forget to escape the backslashes)

I think in Aqua Datastudio v10 and v9 it was possible to enter the unc path directly in the "Select Directory" dialogue. I'm not sure if it was still available in v11.

It would be great if this can be implemented with one of the next stable builds if it can be done without big efforts.

Thank you