Experience? / ONENUO 228WTH Smoke Detector with Temp/Humidity: OBK Flashing, Chip Info, Battery Life

Almost, but not exactly. I know it's inconvenient, because I went through this when doing previous TuyaMCu topics, including this presentation:
[CB3S/BK7231N] Temperature/Humidity Sensor with TuyaMCU - Diagram, Reverse Engin
but you need to manually order those packets. Our Analyzer tool is not quick enough to maintain order.
You can use information from article linked above, especially this paragraph:

Honestly I don't even remember myself this protocol well at the moment, but it is also described on Tuya site, I'll attach the link if I find it.

So, the basic workflow for solving your issue would be:
1. create a clearly described, step by step log of communication with TuyaMCU on Tuya device - but not unsorted, like you posted
2. create the same for OBK
3. Figure out exactly at which point of time communication breaks, i.e. which exactly packet is sent by OBK incorrectly

I see. Let me try it a last time. I can use the existing logs for that, right? Just sort them.

Still not convinced, that the communication breaks. The Wifi-module isn't powered longer with stock firmware, but they manage to transfer data. MQTT is probably not the best way to do it, it seems too slow. Is there no other way to transfer the data?

Furthermore it is still unclear, why the TuyaMcu_setBatteryAckDelay doesn't work although supposed to do.

Have a look, is that ok? (Better check in the Excel-File, as in PDF some lines are missing. But fields are identical)
Of course, for the short wakeup a lot of the function is missing. But even for the long wakeup, there is one line of the connection status missing.