We’ve not been able to reproduce this vert count with our Maya (2013).
Can you list the repro steps for creating your smoothed edge in Maya up to the export.
I’ve tried doing some other methods of smoothing in Max to see if I could replicate and even imported and exported your mesh with the same results.
At this point, I want to narrow down if this is a bug with UE4 or possibly something on Maya’s end.
Thank you for your help!
Tim