Yep the Pi4 will eventually be the way to go but 3CX hasn't officially supported it yet. Understand your hesitation based on your recent experience but myself and many others here use Pi's with a good success rate. VM is definitely preferred if the infrastructure is in place but otherwise a Pi with a quality power supply, good SD card and small UPS works fine.
For redundancy you have a couple options. You can simply put in two Pi's and have half your phones point to one and the other have to the other. That's minimal effort and supported easily in the 3CX UI. IF one dies just re-point the other phones, re-provision and you're all set. If you are looking for something at little more bullet proof you have to setup DNS and SRV records.
For redundancy you have a couple options. You can simply put in two Pi's and have half your phones point to one and the other have to the other. That's minimal effort and supported easily in the 3CX UI. IF one dies just re-point the other phones, re-provision and you're all set. If you are looking for something at little more bullet proof you have to setup DNS and SRV records.
