@mhilbush
I have not changed firmware. Ambient weather do not make the weather stations, nor do they sell or ship outside the USA. People in other countries need to buy under different brands. I purchased an IP observer separately as a spare part with the brand Misol on it for $50 shipped to my door. So I have this weather station which sends the data to a colour screen at the same time as to the Ip Observer unit. Be sure to check the freq matches before buying as they are made in 433, 868, 915 mhz models.
Ambient weather are 915mhz
Aercus (sold in the UK), Pantech and Misol are all 433mhz
The outdoor units only send RF blindly so you can have unlimited indoor units listening to the 1 outdoor unit. If you suspect your hardware has bad flash or ram possibly causing unstability then buying another Ip Observer as a spare part is pretty cheap and would allow you to keep the firmware stock on one whilst playing with a second.
My firmware version has a custom upload feature which does not appear to work. I cannot enter in the URL to the ambient weather website as it appears to have a character limit and I cannot enter the full url. It cuts the URL short. So I tried to enter in a local IP address which fits, but my router logs show that the weather station does not attempt to send packets to the IP I gave it. This would mean you would need to capture and re-direct the packets headed to WU to resend them to your desired URL.
I do not know who writes the firmware and which version Ambient possibly split off from the version I have. It is possible that Ambients is split from an older version and since they made so many customisations they are vastly different to what other brands use. The weewx forum is the best place to ask what version is best.