Great guidelines thanks, just a couple of things on my mind:
1. when merging the ATC folders (e.g. Dep_Gnd and Dest_Gnd) there are some sound files with the same names,
if you're using the FS-ATC file set - but they are not the same actual ATC sounds... so I'm wondering whether,
rather than overwriting repeat file names and losing many ATC sounds, it's better to bulk rename the files in one
of the merging directories before the merge? There are bulk renaming tools like BRU that can do this if its a good idea.
2. for a region like say Europe, I've tried creating a region roughly the shape of Europe in the PATC Authentic ATC editor map,
and assigning that region the 6 folders described in the instrux above... I'm now hoping I have not overwritten the lower level
assignments - such as countries within Europe. The PATC map editor doesn't make it super clear. Will test, but I wish the
PATC map editor handled the hierarchy of Region-Country-Sector-Airport more visibly.