I just tried to extend the example template by adding support for final gather files.
I added this line to the options.js file:
'\n\tattribute string "fg_filename" "' + inShader.finalgather_file + '"\n';
The final gather file is specified in my maya scenes render globals, but the resulting line in the main_objects.mi is
attribute string "fg_filename" ""
Is the final gather option ignored while exporting?