If you force 4G and 5G only, you are likely to lose access to mobile calls. VoLTE interoperability is still lacking, and this issue is unlikely to be resolved without intervention from a standards organization mandating interoperability and default settings. Unfortunately it will only get attention when somebody can't do an Emergency Call.
'Android allows users to disable 2G at the radio hardware level on any device that implements the capability constant, "CAPABILITY_USES_ALLOWED_NETWORK_TYPES_BITMASK". This stops a device from scanning or connecting to 2G networks.
Note: Emergency calling is never impacted. A device still scans and connects to 2G networks for emergency services.'
