Call queues do not ring mobile phone for queue members who have forwarding or simultaneous ring

We are attempting to use a combination of AA and Call Queues to provide an after-hours on-call feature whereby an incoming after-hours call is distributed to two people.  To do this we have these people in a group for a call queue that receives the call from the AA after business hours.  We want these calls to dial their mobile numbers because (1) the SFB mobile client is unreliable, and (2) In some cases these people may need to receive the calls on non-smartphones.  So, these people set their SFB software to forward or simultaneously ring their mobile phones.  But, It looks like the Call Queue function in SFB won't allow calls from queue to forward to mobile phone.

We have also tried doing this using a ghost SFB account that has delegates or team members who receive calls, with the same results.  

Am I missing something?  Are there existing or upcoming features that offer some hope for our situation?

Thanks.