I went ahead and imported a few sprites I made into fusion, and although the option to set anti-aliasing is not only greyed out but also not ticked in the windows property settings (regardless which Direct3D mode), there is some really NASTY anti aliasing going on.
This is an image comparison: Sprite Test.png
The sprite on the left was resized in fusion x4. The sprite on the right was resized outside of fusion by 4x as well.
I noticed Konidias made a similar post back in 2012 albeit for MMF2, and remains unresolved aside from someone recommending him an extension.
Now I don't actually need an extension as I can properly resize my sprites prior to importing, I'm just curious if this is intended or if this is a bug.