@BinaryOS, I have done something similar. My Weather Station (Ambient) lets me re-direct the weather data to a server of my choice. Rather than using weewx as an intermediary, I modified a version of the OS Weather Service to accept a WU data stream directly. I run the modified weather service on my OSPi which keep everything local.
I’m not familiar with Weewx. How does it intercept the WU stream (DNS redirect ?). I’m interested in the comment about ET value. Does weewx calculate this from the WU data provided ?