Just did and the initial run works but it's not able to find the necessary file to actually run.
System.IO.DirectoryNotFoundException: Could not find a part of the path "/Applications/FINAL FANTASY XIV ONLINE/game/XivMods.json".
at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) [0x00164] in <0523ad94f2e04325802cd231c518c8d9>:0
at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.IO.FileOptions options) [0x00000] in <0523ad94f2e04325802cd231c518c8d9>:0
at (wrapper remoting-invoke-with-check) System.IO.FileStream..ctor(string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare,int,System.IO.FileOptions)
at System.IO.StreamWriter..ctor (System.String path, System.Boolean append, System.Text.Encoding encoding, System.Int32 bufferSize) [0x00055] in <0523ad94f2e04325802cd231c518c8d9>:0
at System.IO.StreamWriter..ctor (System.String path) [0x00008] in <0523ad94f2e04325802cd231c518c8d9>:0
at (wrapper remoting-invoke-with-check) System.IO.StreamWriter..ctor(string)
at System.IO.File.WriteAllText (System.String path, System.String contents) [0x00026] in <0523ad94f2e04325802cd231c518c8d9>:0
at xivModdingFramework.Mods.Modding.CreateModlist () [0x00067] in <e7087d1cba03440a94b4ddd624a8bfd5>:0
at xivModdingFramework.SqPack.FileTypes.Dat..ctor (System.IO.DirectoryInfo gameDirectory) [0x00019] in <e7087d1cba03440a94b4ddd624a8bfd5>:0
at xivModdingFramework.Helpers.ProblemChecker..ctor (System.IO.DirectoryInfo gameDirectory) [0x0001e] in <e7087d1cba03440a94b4ddd624a8bfd5>:0
at FFXIV_Modding_Tool.Commandline.Arguments.PreviouslyModifiedGame () [0x00029] in <1efd7f5278184069a7bb4e8f4d373139>:0
at FFXIV_Modding_Tool.Commandline.Arguments.ArgumentHandler (System.String[] args) [0x0080b] in <1efd7f5278184069a7bb4e8f4d373139>:0
at FFXIV_Modding_Tool.MainClass.Main (System.String[] args) [0x00036] in <1efd7f5278184069a7bb4e8f4d373139>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.IO.DirectoryNotFoundException: Could not find a part of the path "/Applications/FINAL FANTASY XIV ONLINE/game/XivMods.json".
at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) [0x00164] in <0523ad94f2e04325802cd231c518c8d9>:0
at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.IO.FileOptions options) [0x00000] in <0523ad94f2e04325802cd231c518c8d9>:0
at (wrapper remoting-invoke-with-check) System.IO.FileStream..ctor(string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare,int,System.IO.FileOptions)
at System.IO.StreamWriter..ctor (System.String path, System.Boolean append, System.Text.Encoding encoding, System.Int32 bufferSize) [0x00055] in <0523ad94f2e04325802cd231c518c8d9>:0
at System.IO.StreamWriter..ctor (System.String path) [0x00008] in <0523ad94f2e04325802cd231c518c8d9>:0
at (wrapper remoting-invoke-with-check) System.IO.StreamWriter..ctor(string)
at System.IO.File.WriteAllText (System.String path, System.String contents) [0x00026] in <0523ad94f2e04325802cd231c518c8d9>:0
at xivModdingFramework.Mods.Modding.CreateModlist () [0x00067] in <e7087d1cba03440a94b4ddd624a8bfd5>:0
at xivModdingFramework.SqPack.FileTypes.Dat..ctor (System.IO.DirectoryInfo gameDirectory) [0x00019] in <e7087d1cba03440a94b4ddd624a8bfd5>:0
at xivModdingFramework.Helpers.ProblemChecker..ctor (System.IO.DirectoryInfo gameDirectory) [0x0001e] in <e7087d1cba03440a94b4ddd624a8bfd5>:0
at FFXIV_Modding_Tool.Commandline.Arguments.PreviouslyModifiedGame () [0x00029] in <1efd7f5278184069a7bb4e8f4d373139>:0
at FFXIV_Modding_Tool.Commandline.Arguments.ArgumentHandler (System.String[] args) [0x0080b] in <1efd7f5278184069a7bb4e8f4d373139>:0
at FFXIV_Modding_Tool.MainClass.Main (System.String[] args) [0x00036] in <1efd7f5278184069a7bb4e8f4d373139>:0
You may want to up the Docs to say the GameDirectory config value or -g option needs to look within the .app file. The full path is similar to:
/Applications/FINAL FANTASY XIV ONLINE.app/Contents/SharedSupport/finalfantasyxiv/support/published_Final_Fantasy/drive_c/Program Files (x86)/SquareEnix/FINAL FANTASY XIV - A Realm Reborn