category options

[DFletcher-UK]

I am using the 'leafem' addGeoRaster function to add rasters to my maps. When I use addOpacityControls(category="image"... I do not get controls for the opacity of my rasters. I can't find a list of the possible category options - the documentation only mentioning "tile", "image", "marker". Should "image" work, or is there another relevant category, for addGeoraster(), please? If I used the group= instead, the controls appear, but I would prefer to use category=, as this would be more suitable.