Um, not quite. Map#282 HeloRampLightSplash_spec.psd file is the one.So, if I follow this correctly, the "sandstone" texturizer is applied only to the HeloRampLight_LM.psd file that is intended for use in "Self-Illumination: Map #6" as seen in the GMAX Material Navigator in your Post #6 above ?
Yes, that is one method, although if using the FSX Imagetool the "flipping" is done automatically.And IIUC, after that material (and all others in the project) have been mapped to the 3-D model in GMAX, when final output files are created, those mapped *.psd files must all be copied, "flipped", and converted to *.DDS files for use in FSX using a graphics utility (ex: FSX SDK ImageTool) external to GMAX itself ?
Personally I use the nVidia DDS plugin and simply "flip vertically" then SaveAs DDS directly from Photoshop. It's much easier, faster, and less effort...