S3D has always been great about supports, until recently. I am not sure if this lines up with 4.0 or if it started happening earlier than that, but its only putting a small fraction of the supports that are needed by the model.
Here is an example of a dragon in S3D. There are quite a few areas on this model that need supports that S3D is ignoring. The most obvious being the nose area.
The same model in Cura, puts supports exactly where I would expect them.
The site doesnt allow files over 3 MB to be uploaded, so I cannot attach the factory file, but here is the model I am trying to print: https://www.thingiverse.com/thing:1249581
Note that this happens with nearly every model I try and print that needs supports, not just the one in this example!