We use Eagle to generate a .emn and .emp file, then we build the board model in Circuitworks. In Solidworks 2018, prior to SP3, it would build the model quickly. Starting in 2018 SP3, during the "adding components to assembly" step it opens every single instance of every component's .SLDPRT momentarily in a separate window. Thus a board with a couple thousand components takes tens of minutes to generate the .SLDASM, whereas previously it may have only opened each type of component model once. Is there some setting that can be changed so that it doesn't try to open every instance of every component?