Spot color separations are the former - each color goes on a different layer that’s then output on a template for films. It’s all solid PMS colors and/or tonal values over a solid (usually) white underbase and how to output raster halftones without a RIP.
I do plan on teaching simulated process and WCMYK in one of the advanced classes, where we pull channels in Photoshop and generate photorealistic separations with a dynamic underbase and then output high LPI halftones to films, but I’ve got to find a RIP software sponsor and do a lot of writing before I can get a class together for that.