I use the Replace downlink queue in the TTN console’s Schedule downlink Insert mode to quickly drop data and cause packet drops. Using the Push to downlink queue (append) does not lose data. Why?
What if I want to always be in Push to downlink queue (append) mode? Because whenever I re-enter the Schedule downlink interface, I will be re-selected to replace downlink queue mode.
Replace downlink queue - If a message are scheduled already it will replace it with the new one you send, if it weren’t sent to the node.
Replace downlink queue is the default setting on the console, so it will go back to it every time.
Normally you will actually send your downlink from your App not the TTN Console. In the JSON you send to your node you can specify all the settings, like “Replace downlink queue” or Push to downlink queue (append)