I’ve chatted with several different US Mobile reps, and they stated that IMS is currently in beta testing and agree that it should work for my plan, equipment, and intended use. I have tested it in the US, and it worked well, mixing a Verizon US Mobile (Shared Warp 5G) voice line with a T-Mobile data line. It is not WiFi calling and requires two distinct lines, and any two lines should work as long as the device is capable. I’m currently using 2 T-Mobile lines in China right now, but you can mix & match carriers. Unfortunately most Android phones are not capable of IMS due to lack of dual sim, dual standby functionality. As I mentioned, I have been using it for well over a year internationally, and with excellent results overseas. One of the best roaming features is you may call another US number that is also roaming internationally while you are roaming, and neither line is charged.

i screwed up my testing plans by not confirming my 911 address and making a WiFi call prior to my trip departure. I was chatting again this morning with 2 US Mobile reps and thy can’t override that requirement. I had just switched plans the morning of my departure to the Shared Data plan and forgot about the 911 side of it.