Ttgo-lora32-v21 lora payload missed

the goal is to send a signal from a reed-contact to iobroker using lora and mqtt - something similar was described in here or in the mailbox contact youtube movie with as little overhead as possible.

edit:
found one reason of my problems, obviously the msg has now to be sent as json

{
“model”: “ESP32TEMP”,
“id”: “ESP32_MAC_ADDRESS”,
“tempc”: “TEMPERATURE_IN_CELSIUS”
}

this way I get all msgs on mqtt now,
but only tempc is displayed on oled and webui mainpage

"Auto-discovery, when the node sends an id and one of the following keys … " here only tempc seems to work or is this only meant for HASS - (which I am not using here) ?

Lora node ID as a subtopic makes sense - very useful in my case.