I can’t image Ilford Smooth Pearl being much worse or better than any similar paper for gamut, unless you are willing to do your own custom profiles.
If you want to see the extent out of gamut areas with various papers, just download and softproof with the canned profiles for your printer from Hahnemühle, Canson, Harman, Ilford, Moab, Innova, Inkpress, etc, etc.
Brian A