Join the SA Discord, we have our own MQTT.
The public one only uploads to Meshmap, ours links to a SA map and the Liam Cottle Map
https://discord.gg/rrqKfNWw
I don't know what implementation of mesh you used but you will hardly flood a meshtastic network with a couple of sensors.
I rebroadcast all the messages from CPT via MQTT in Midrand and still remain under 10% airtx util.
Meshtastic is coded very well and nodes don't rebroadcast a message if...