There’s already a new way to enable VoLTE on Pixel phones

TL;DR

• Google broke the Pixel IMS app that enabled VoLTE/VoWiFi on unsupported carriers, but the developer has already released a new workaround.
• Google’s October update patched a loophole that the app exploited, specifically blocking the “shell” user from calling a restricted internal API.
• The new fix bypasses this restriction by “laundering” the API call through another component, so the system doesn’t detect it coming from shell.