I suspect direct printing from B&W slides might involve some contrast masking, since it's described as a high contrast paper. That's not unusual for positive-positive processes. There may be some way to bring it down with a low contrast developer. For pinhole, high contrast would be desirable.
I'd be interested in shooting it in camera with a lens just to have a print that is a unique first-generation image.
I've tried this paper. Unless you are interested in some special effects, you need to pre-expose (fog) the paper first. I suggest an in-camera Zone II or III pre-exposure with a diffuse filter, such as the DIY filter in the attachment. Ilford suggests a pre-exposure in the darkroom prior to loading the paper into the camera. I found that to be cumbersome.