LTE is quite standardized, although VoLTE is far from it. IMEIs can be spoofed. VoIP numbers are a thing (e.g. voip.ms, or google voice if you can go without em

LTE is quite standardized, although VoLTE is far from it. IMEIs can be spoofed. VoIP numbers are a thing (e.g. voip.ms, or google voice if you can go without emergency services). I forget if IMEI spoofing is a felony. So much policy on the books it would take me months to know for sure.