Great feature request and easy to implement!

Yesterday we have announced a whole new army management subsystem, which makes everything easier. (
more info) (Note that the old, invitation based system continues to work, and you can download the old version of the client too, but I recommend to change to the new version) .
This means that echo is not usable in that way anymore, but we will change its behavior to allow testing of the new system. The plan is that he will use the 'echo' security code, and he will be always near to you on the map. Together with this change your request will be implemented too.