When exporting a complex file from Blender to STL, S3D has an issue with the auto updating. I get the 'reload modified file' popup as expected (great, great feature for me) but at times the pop-up will repeat five or six times for the single Blender export requiring me to answer the prompt for each one. most of the time I only get one pop-up in S3D.
Seems like some sort of timing issue where S3D picks up the new file a few times while the file is still being created.