The difference between silver and gold electrolysis is that silver oxide has very low solubility whereas gold chloride solubility is very high. So you don't need a large anode area to prohibit precipitation in the anodes boundary area.
Gold and silver also differ in the amount of electrons needed to create their compounds. Silver needs one, but gold needs three. So a small anode creates a higher density of chloride ions at the surface of the anode.
Statistically, every electron (hydroxide) releases one atom of silver as silver hydroxide.
It takes 3 chloride ions to release one atom of gold as gold chloride.
Suppose a gold atom picks up one chloride. Unless it gets another two, it will remain bound to the anode. But that atom now has lesser charge to attract another chloride, and if it does, it will have even less charge to pickup the third. So we want to concentrate the chlorides into as small an area as possible.
To further add to the problems is that as the electrolysis is continued, the sodium chloride becomes used up and replaced by sodium hydroxide which will not make a soluble gold compound. This is the reason that Faradays law does not predict an accurate run-time.