The problem with “grippy” materials is that they are usually at a lower durometer. These materials will tend to flex and I doubt that would be acceptable for a climbing application.
Have you thought that the part would be molded in an ABS, not sure if it needs to be glass filled (I hate the look and feel of glass filled polymers), but then overmold santoprene, and give you that grippy surface. This would also give your product an increased appearance and value to the customer.