Is there a way to update the displayed customer name (firstName, lastName) in an Architect chat flow? For example, if I don't pass those attributes when I create the conversation, but through a data action, I get the name and want to update it. (If I don't pass these attributes the default value is "Customer")
Unfortunately no.
The firstname and lastname are used to create the displayName when the chat is created.
The display of the name ("Customer") only changes (I think) if the conversation is associated with an External Contact.