Limiting the number of bytes on the uplink

(1) Sorry but that is not a LoRa or LoRaWAN use case…. Don’t even attempt it

Absolutely….

See (1)!

Use the airtime calculator….even with zero payload and just using FPort value to indicate some signal/condition au915 is max 647msg/day at fastest SF7…. As stated NOT LoRaWAN use case….
https://avbentem.github.io/airtime-calculator/ttn/au915/0