As a former Merchant/Restaurant Researcher, I found that the cases in which merchants need to chat with customers during an ongoing order are:
For changing menu items if any has run out,
To clarify the notes the customer writes in the order, and/or
To inform customers if the order preparation takes longer than expected.
From the Indonesian Merchant Apps I’ve researched and observed so far, they have not catered to these use cases efficiently. This inspired me to create my rendition of a Merchant <> Customer Chat Interface by considering what the merchant and customers truly need when communicating with each other.
‘Quick Chat’ with canned messages gives better accessibility, especially for users in a hurry. Entry point to menus is also accessible from the chat room for customers to use without having to exit the chat.
Further improvements can be made by locating the ‘Quick Chat’ on the bottom of the screen for better thumb accessibility.