re: big scenes
Datasmith already handles scenes with 20,000+ objects and 100M+ polygons, it does assume you have a computer with at least 32Gb for something like that. When we build the Maya version, it should be same capability.
re: game scene?
You don’t have to perform anything special related to using data created by Datasmith. It is just a UE4 asset like all other UE4 assets. You cannot use a source-code compiled version of the engine, if that is what you mean. Datasmith only works with the binary we release.
re: new Maya Live Link
That only works with animation data AFAIK.