Without ACK/NACK, message is lost?

Ok I will try that commit and let you know how it goes.
There is something that I am thinking… What I have done is take a file and separate it into small pieces using Kotlin. These pieces are then sent to the Lora device as separate packets (this is where I am trying to develop the meshtastic code, with problems!) I think what would be good is if the firmware can understand if the packet is part of a file, or if it a regular message. For example, if at the head of the message there are certain characters (ie $T%%), then when it sees this it doesn’t send like a regular messages (with 3 attempts at sending etc) and instead it will send it more than 3 times to ensure it is sent and also ACK/NAK isn’t necessary.
This is my goal… do you think it is possible? I’m always working with Android and Arduino, and not so familiar with C++, so all your help is really appreciated.