I've just tried it out, but I'm unable to make phone calls. I was able to receive a text from Vodafone (UK), and also check my balance, on-screen with *#1345#, but if I call 1345 (audio balance), it just hangs, and I am also unable to hang up. The device is still responsive, but pressing the button to hang up has no effect.
I tried to install Machines vs. Machines, and noticed there is no sound, so that is possibly also what's causing phone calls to hang as well. I followed the post-installation steps and double-checked I typed the right commands. The only extra command I did was a 'apt update'. I also checked that the installation of 'pulseaudio-modules-droid-24' persisted.
Ubuntu 19.04 using the system's compiler rather than the prebuilt one.