Short answer
Before a restaurant or cafe switches POS, it should test four things with real orders: a busy kitchen ticket with modifiers and a split payment, recipe costing that updates when an ingredient price changes, selling with the internet off, and a refund that corrects the drawer, the order history, and the stock.
Does a real order reach the kitchen cleanly?
Do not watch a clean demo order. Add sizes, notes, modifiers (options such as an extra shot or no onions), split payment, a held table, and a late ticket. The kitchen screen (KDS, kitchen display system) should make the rush calmer, not give staff another place to check.
Does recipe costing update when a price changes?
Pick one dish with a sauce or prep item. Change one ingredient cost and see whether the dish margin updates. That one moment tells you if the inventory module is serious.
What still works when the internet drops?
A cafe in a mall or market cannot stop selling because the router restarted. Confirm what still works offline and what needs a connection.
Does a refund correct both stock and cash?
Refunds should correct the drawer, the order history, and the stock movement. They should also carry a staff name.