Custom phone templates are often required for things as simple as changing the backlight duration. Yet once you choose to go down the custom template route, 3CX considers you an unwanted stepchild. Your phones all turn red in the Phones menu. You cannot provision using PnP, which means you cannot re-provision through an SBC (see this thread). Haven't even tried with STUN. I appreciate that 3CX develops custom templates and that these must serve as a reference point for support. But please adopt custom templates as legitimate members of the family: 1. When adding or choosing an extension from the Phones page, allow specifying any matching template including a custom template. 2. Allow re-provisioning of all phones that use custom templates over LAN, SBC, and STUN. 3. Choose a different color, maybe blue, for supported phone models with current firmware that that are custom provisioned. This will allow quickly identifying the phones that really do need attention vs. the ones that are intentionally provisioned with a custom template.