I understand that part..but...you are in the USA and still connected to your normal cell network,

Comment was that it is possible to use a cell network OUTSIDE the USA and not pay to connect to that network. Data is not the issue....voice phone calls is. Using wifi calling in AP mode removes the need to shut off data since it will be shut off by default and will use wifi for all the data (and calls) you need ...at zero cost to the USA

Example/question : I am in SXM and at the new BBB and have my data AND AP mode shut off. Someone calls me from home.....I can receive and answer the call and there will be no charge to either party...or $1.79/min to both?