Well, I was finally able to make it work by:
1) Uninstalling the compressed textures mod;
2) Starting a flight with the A359, normal uncompressed textures;
3) Using the Ini Manager install the compressed textures again - after having run the aircraft at least once after base install into the sim.
So, apparently, after base install with default textures we have to load the aircraft at least once into the sim in order for then being able to use the OPTIONS and opt for the reduced textures mod.