Meshtastic's default presets (LF20) are only functional in a mesh up to roughly 50-80 nodes in real world use. in 2024, there where ~1000 Meshtastic nodes @ Burning Man. If all of these nodes where on default firmware, the mesh would have been 100% unusable, and it is likely that even nodes that are physically right next to each other would have been unable to send messages to each other.
In addition, we are implementing other firmware additions as per Meshtastic's “Event Mode” firmware guidelines as seen here.
The BurningMesh firmware will be based on Meshtastic 2.7, which is being promoted to stable in mid July. Once that is complete, the “finalized” version of the firmware will be released, and there will be a website in which it can be installed (similar to the meshtastic web flasher). The firmware will most likely be continually updated until the burn.