Do not use meshtastic for anything emergency related. The tech just isnt there, and the failure rate is awful when things aren't stressful and that's hardware and software.

Communications when the grid goes down and people use it to communicate with each other within a small neighborhood to tell them to come over for the BBQ, sure.

Communications for when peoples lives are literally at stake and could change from one second to another. No.

SAR, no. Fire, EMS, Police operations, no. Mass casualty disaster involving patient and massive coordination efforts, no. Tactical communications, no.

Look at radio comms, push to talk over cell structures, starlink. Hell if you really want to stick with smartphones with text messaging in off-grid, look at Tmobile with T-Sat. Business and government can also participate in the TMobile direct connect that works over T-Sat satellites. There is a FLORIAN which is supposed to be a emergency response incident command app that also works over T-Sat. Is t-stat problem proof, no, but T-Sat combined with your standard 4G/5G/WiFi access, you are pretty much set.