I’m not sure where the Phone Apps Module left off as far as supporting other brands besides Sangoma but I’d figure I’d still post my issue just in case. I’ve only tested this on Yealink T46G. If I’m on a call and another call comes in I cannot park the current call using the Parking App button. If I Program a key with DTMF ##70# it works as expected. I can provide logs if needed.
This would be a issue with yealink. All we do is say he take active call and transfer it to this slot number with the app. It would be their phone and firmware that has to handle that correct.