It does help only after restarting xCode, then on the next run it'll take a while to rebuild the content of this folder (what will delay the run on the device), and after that it does work much faster.

Hi Quinn, unfortunately this buggy forum decided to scroll the screen at the moment I've selected the "accepted answer" so it selected this one instead of the new one I've just published, but I can't change this selection... Please change it for me if possible.