How to integrate STM32L0xx and STM32F4xx with Domoticz and MySensors?

Hello,
I need to realise a visualisation of low variability data coming from a dozen sensors. I rejected proprietary solutions such as TFT+GUI+TP due to the lack of compatibility with different systems and the additional costs associated with the development of hardware. After analysing the available solutions, Domoticz + MySensors fell due to the possibility of working under different systems (Android, Linux, Windows) and the possibility of supporting the sensors and actuators I have in the system. In addition, data encryption, control of operation via hearbeat and acknowledgement of data reception are all necessary elements to improve security and reliability.
Unfortunately, the AVRs don't suit me and I would like to replace them with STM32L0xx in small battery-powered nodes and STM32F4xx in gateway and large continuous-powered nodes.
The code used in MySensors works under Arduino, but trying to rewrite it for STM32 under Eclipse has overwhelmed me. On the one hand, too many functions are invisible or redefined with #define and then buried somewhere deep, on the other hand C is mixed with C++ and monsters of type appear:
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There is mention on the MySensors site of attempts to approach this by 2 people: freynder and tekka. But they haven't published anything concrete yet. There has only been a list of necessary file changes for a few months.
For the time being, I'm interested in USB data transfer based on VCOM. MQTT I am not even trying, even less so with small data volumes (<5kB/h).
ESP doesn't interest me because I have a lot of energy constraints: maximum current is 50mA, operating time >6 months, TDM-based data transfer where the gateway manages timing to avoid interfering with other nodes.
A question for 100 points or more:
Can any of you point to readable code for a gateway or single node based on any STM32 and compatible with Domoticz or another comparable combo (HomeAssistant or OpenHAB)?

The first link is a dubious consideration for the nRF24L01+ clone range The author mentions something about STM32, but the link to the repository is only about nRF24 support.
I am very familiar with the topic in the second link and have mentioned it before. This is where freynder and tekka have been hinting something about support for this old chip which is the STM32F103C8.
What I find most tiresome is all the magic libraries used to support STM32 peripherals in the Arduino environment, e.g. mapple. It's even worse than HAL.

In fact, I need to get along with a Domoticz or similar type controller. I decided to go with serial communication via MySensors because it seemed the best documented, easiest and with quite a lot of support. My mistake. I can painstakingly recreate the communication by sending predefined data to the controller and analysing the response, but this is a fool-proof solution. On the other hand, I don't see much point in digging around in the Domoticz sources to find the full data flow for the protocols I'm interested in. If I were proficient in C# or Python, I'd probably write a plugin for the custom communication system I use between devices, which is more akin to USB support than MySensors. I'm not giving up and the work will continue.
I often use boards with the STM32F103C8 for prototyping. Thanks to the pin compatibility, sometimes I just swap the chip for one closer to the target. No competition at this price.
BLE does not interest me due to lack of repeater capability and severely limited range.

I decided to develop a MySensors-compatible gateway function for STM32F7/H7 based on the protocol available in API . The radio operates on 433 MHz or 868 MHz. It works reasonably well. The only drawback I've encountered is the ST-Link V2 used for data transfer can crash after a few days of operation, so I use a VCP on a hardware USB uC. Perhaps the just-entering St-Link V3 will not have this problem.