Here's a quick test I did using a single smoothing group synced workflow between SP and UE4 Bartalon is correct, the smoothing artifacts will be visible on your normal map but this doesn't matter in a synced workflow as both SP and UE4 are calculating the tangents/bi-normals in an identical manner(mikkt) NM is 16bit…
Synced baking is perfectly fine provided the end result after compression looks good. The only way to know is to take it into an engine like UE4 and test it yourself.