Not sure what do you mean with "better integration" or that we should wait for PMDG. None of these features would require help from PMDG. The only thing we would really need help from PMDG, would be the syncronized refueling, and the bypass pin simulation. They don't seem to be interested, opposite to FS Labs, which already feature the bypass pin integration with GSX and recognize the GSX refueling process too.
1) the side cargo works just fine, but must create a custom configuration for it, because the default configuration we made for the 747F uses both loaders in the right, but nothing prevents you to move the door to left, GSX supports loading cargo from the left side since many years.
2) supporting the nose cargo would require a major update to GSX so, it's something for a future version.
Note that, regardless how you configure the airplane, you will always have TWO loaders IN TOTAL, due to limitation of the FSX SDK which would be too long to explain here. Having more than 2 vehicles of the same kind is something we would like to do, but it will probably require a P3D-only version, which is something further down the future...