Lets see. I re-did the model, made sure there were no UN-needed areas within the model that did not define the outer shell only, and remade the textures.
All textures were applied from one sheet, size 4096x4096. The model size (SKP) went up dramatically from 19mb, to 87mb. That's not going to work. I'm still having export issues where SU crashes at 57%.
I then reduced the template sizes to 2048x2048 for a test. SU still crashed at 57% on export. I tried saving the texture templates as .JPG, .PNG, .BMP, and PSD. SU still continues to crash.
To further the testing I exported as 3DS fine. Amongst others that also exported without apparent problems. I was unable to test beyond export.
I was able to get the .DAE exported once. The file size was very small, but it did export, and imported into MCX fine. But, there were no textures being displayed on the model when it was displayed.
I also made sure that there were no anomalies prior to export. All cameras, shading guides, etc = OFF so they did not have the chance to get exported with the model. Nothing I try seems to work
Also, there are settings within SU that allow textures to be displayed in high resolution. Not exported as such due to Google model limitations only. This (I think) also affects .MDL files that are made for FSX.
This is frustrating to say the least. I can't seem to find an answer anywhere that's relative to the situation I'm experiencing.
Next phase, re-do the model a third time. Ground up renovation and applying the textures as I progress, export the model after each stage. There has to be a logical answer.
Just to be sure the download/install was not corrupt in some way, I will also re-download and re-install to try to cover all the possibilities.