Is there any productive way to edit or update UI texts and messages when a locale is added? Say, I have English and Russian Locales existing in my application and later I decided to to add French Locale in my app. It seems that we have to update all the texts at respective screen level once by one. Am I missing anything here e.g. an option to visualize all of those texts in different languages at one place to edit / update?
You can use our translation tool that allows you to gather all messages in a Excel file and create new messages files after translation.
See https://github.com/cuba-platform/translations. You need to follow the Full translation section, but when reading existing messages, specify your project root folder in -d parameter.