Dear Support,

On Mobile SDK / Website, when the website language changes, default messages and chat widget properties are translated automatically,

But if you use, custom messages, you have to create another website on SalesIQ (Mobile or Web) or you should not use any customized message if you want to serve in different languages

A few months ago; Desk Team has created a Beta Version of Multilingual Knowledgebase which gives customers to manage all the articles in different languages. 

A system like this will work on SalesIQ  as well for customized messages. Your customers are giving service in different languages and they are in different industries, city's and countries. The message is important for different cultures and societies.

Another way is; you can create more APIs as you serve in Mobile side on custom feedback messages.

Thank you