Bad news: I just tried to convert your mod, Zeko, but no chance. I have done over 150 PC -> Mac GR Conversions but here I don't have a clue, why it isn't running.
I have shortened the too long filenames for Mac use. No problem at all, converted the sounds etc.
One obvious thing, is that you would have to reexport the menu backgrounds, shell pics, briefing pic.... The Mac only allows rsb files with A1R5G5B5 (Alpha - Red - Green - Blue Channels) otherwise the textures are totaly screwed. But the biggest problem is that your maps don't run. Your maps won't load. I have tried to delete the sht files, removed the unlight.maps, removed the Main_Menu folder from the Maps folder, which caused a crash even if you only select a Wild SKull Valley map in the map selection, etc but no success. Maybe it is the gigantic filesize of your maps!? - That shouldn't matter but I noticed that you maps are almost twice as large as the original ones.
Well, I don't know how different you have made your map than other modders have done them in the past, how close you kept with the GR 3DSM guidelines/polycount/lightning, whatever it is they don't work and unfortunaly I can't do anything at my end at the moment...
@ Loto, just mail me your conversion if it is less than 5 MB otherwise host it somewhere for a short period and I gonna download it from there and then add it our Mac Downloads. Send me the link via email please.
Regards,
Mauti