Shower Waterproofing

New here! I'm getting ready to tackle my first walk-in shower (I've tiled several tub/shower in the past). I'm planning on doing a RSS foam shower pan (option with the topical waterproofing membrane applied) and banding the shower pan corners and edges with RSS band. Perma base will go on the walls. Hydro Ban will go on after that. Really similar to the shower Isaac did videos on where he used the same sort of process, with the exception of the sheet membrane on the shower pan. My questions is, do I need to apply Hydro Ban to the shower pan, or only to the band around the pan, or??? Since the shower pan is already waterproof, does it still need waterproofing? Would it be best to just apply the sheet membrane to the shower pan too?