Currently only delegated user permissions are supported, and this is very sub-optimal for bots and service applications that need to monitor Teams presence of users.
I just read this thread so far and laughed as hard as could be, hurting my ribs. Why? Because I'm going through these exact same hoops everyone else is here and it is maddening. Yes, I'm in a position where delegated permissions would work, by why? You want me to subscriptions for each user and re-up it every hour in my app? Really? Or.......... once.
Let us make that decision. Is presence info REAAAAALLY that important?