Hey Bill,
We do not provide explicit release dates for features which are currently being engineered. Using this approach prevents us from releasing poor quality features, or negatively impacting our relationship with our customers and developers in cases of delayed releases due to unforeseen circumstances.
We are actively working on this feature, and you can follow our blog for new release announcements:
https://blog.ringcentral.com/ (there is a subscription form on the right side of the page where you can receive email notifications of new blog posts).
At this time ringcentral only support a 5 digit extension. I also need the ability to enter 6 digit extensions. Will that be possible?