[mato]

AFAICT from the Internets, BB10 OS actually supports VoLTE, but there's no way to manually enable it. Given the support status of the devices no carrier will provision VoLTE on it for you these days either, so we're out of luck.

[rootsudo]

I wonder if it's something in the baseband, if you can get QXDM to talk to the modem, you could probably enable it.

You just need to enable a diag modem on bb10, if you can, then voila.

https://mt-tech.fi/en/modify-sony-xz-xzs-xz-premium-xz1-and-...

Something like this.

https://forum.xda-developers.com/t/guide-qxdm-port-activatio...

[aosmond]

That brings me back. I worked on it way back when. The IMS stack works over WiFi too; it could probably work with any generic SIP provider and hook into the native phone app.