To avoid exploits, the mod removes the gold on the merchant as soon as you quit the barter menu. The final effect is the gold added on the merchant adds up with the barter gold, giving the merchant more gold. It's like reverse-pickpocketing, an invisible hand place gold in the merchant's pockets instead. To circumvent this problem, this mod adds gold directly on the merchant before the barter menu appears.
Since the barter gold is technically not on the merchant, you can't pickpocket that gold or temper with it directly, at least not in a live fashion. Merchants keep their barter gold in the same hidden chest they use to keep their inventory, which means it's governed by leveled list laws. The delay before the barter menu is also gone, just like Vendor Sale Delay - Gone. Once you unlock the Master Trader perk, the gold replenished will be multipled by 3. To resplenish gold once a merchant doesn't have enough left, simply exit the barter menu and ask again What have you got for sale? In simple words, the barter menu has been modified so every time you ask a merchant What have you got for sale?, it refreshes the merchant's gold.
