It never was an actual "valid" option as files on PTS are new files (or old if not yet patched with next updates and live was patched meanwhile) and thus you would have wrong files/data.
Or it checks the CRC and says "not the ones I want" and will just redownload either way
It maybe that some of the videos and sounds could be copied
You can try to copy the
vo_<language>, e.g. vo_en or vo_de
and vo_soundsets folders
and see if the launcher will check those CRC and find they are okay or need any update.
But I would never copy any of the other files and folders unless you want to get a courrupt install.