Craig hit the nail on the head.... and it's pretty much preference ! I don't usually install fibre pads on customers cues regardless if it's ivory or not unless absolutely requested....
It's original intended purpose was to protect the ferrule, commonly with ivory, but everyone I know that uses an Ivory ferrule without a pad, doesn't let the tip wear down to the end before replacing it, and never had a problem... so the need for the extra protection is not necessary in my professional opion.
- Eddie Wheat