BBS & Mail for Meshtastic!

I'm not an expert by any means, but from what I have learned so far I can see that there is some logic to how the nodes process and route the messages to avoid congestion, and there are some options that one can make (like selecting specific frequency sub-bands) to make a more private mesh run smoothly.

I suspect that a lot of the issues that you read about are related to mis-configuration.

Examples:

• You are setting up your first meshtastic device and you want to find other people quickly, and so you of course set up your device to downlink messages from the most popular MQTT server and make use of the default settings - like hundreds of other people around the world. This overloads your device because it is downlinking MQTT messages faster than it can process them, and it can become non-responsive.
• You purchase a node and want to contribute to your local mesh, and you are lucky enough to live in an area that already has a dense mesh network. Since you want to contribute, you set up your node and make it a "router", and use a common configuration. But your node is not actually very well positioned, and the "router" type has preference over other nodes. Your node can stop nearby stronger nodes from broadcasting. To make it worse, at some point there were problems because there was a Router Client setting (see: [Feature Request]: Admit Router Client was a mistake) many users did not understand the behavior of the router node and this lead to some meshes running into trouble. So, as the mesh grows, it becomes more likely that you will introduce nodes with sub-optimal configuration into the mesh.

There is possibly some threshold at which a mesh really does grow so large that even if properly configured it may be problematic, but, honestly, I don't know if this has happened. In my area we are certainly not close enough to having a functional mesh, so I have not experienced these limits.