Yes, it is possible, but if NVG addons cannot be "patched" in addon config, you could give user option of replacing realistic high res NVG. You just need to replace in-game NVG with yours by giving users automatic batch file that de-pbo's their data3d.pbo, replaces the NVG model with yours and then pbo's it back up. Kegetys did this with his amazing sky mod. If you do this...download Keg's sky mod to see how process works and to get batch installer to modify. Since replacing NVG in O2, you can change textures to whatever you want (you don't have to use texture references to data.pbo NVG). I strongly suggest you use DDS DXT3 textures instead of PAA or JPG, but if your overlay requires more than the most basic transparency, use PAA/PAC. All mods should use DDS, it provides 16 times the color of PAA with only 2x the size, and who knows what PAA is like in VRAM--does it get decompressed...DDS doesn't.