For those who need EXP50 in Endpoint Manager, I created a thread on Yealink’s forum.
Maybe if a lot of people request it, Yealink will go on with the Endpoint Manager certification process (or whatever it is called).
http://forum.yealink.com/forum/showthread.php?tid=43450
Do not hesitate to comment the thread on Yealink’s forum to put some pressure.