I reach mini and iPhone 14 communication

I would say “no”, since the only messages that the iPhone 14/15 can send or receive by satellite are those to/from Apple’s ‘SOS Center’.

I don't understand the question. The M1 is an inReach device. It can send and receive messages via the Iridium satellite network. That is true whether or not the device is paired with a phone.

The M1 pairs with the legacy Earthmate app on both iOS and Android. The paired phone can be used to facilitate sending messages. In effect, it provides a virtual keyboard for the M1 - which makes it a lot easier to compose messages. I believe the Earthmate app also displays messages sent and received by the device.

Unlike the M2, the M1 cannot be used with the Messenger app. So the whole confusing "Internet vs. satellite" mess does not come into play with the M1.

None of that has anything to do with the inherent SOS-only messaging which is built into the phone. 

5403424 said:

Can we send messages between the mini and iPhone and receive them outside of cell coverage?

between means for me that you want send a message from the mini to the phone without the phone being connected to some network?

No this can not work. 

Neither you can send a message from the phone to the mini without any connection to network of the phone.

The phone is connected by bluetooth to the mini and acts as akind of remote control of the mini.