maybe I‘m missing something, but I know there are OTA DFU client libraries for Swift, ObjC, Java and Python.
But it looks like there is no DFU lib from one nRF52 to another in C or C++ - is that correct?
You are correct. Currently, there is no "nRF52 to nRF52" setup provided in our SDK. To be more precise, there is no DFU client implementation to go with the existing DFU server implementation.
Although the transport layer is defined.