I have scanned the features Requests and have not seen this as a request.
The ability to do a blind transfer to any extensions voicemail as an option when selecting a current call in the Assistant.
and or the ability to drag and drop a current call onto and extesion with like the left button and it go directly to voicemail. This simply ability to send to anothers voicemail, would save a lot of pressing *4 ext#, my client is an law office and a lot of calls after answered are sent to individual voice mail.