Interesting solution. I must admit I thought that connecting directly to the RS485 looked like a good idea. I didn’t realise it used Modbus as a protocol. How did you know which registers to read?
I guess the only downside for some might be losing the ability to use the Ginlong app. Personally, despite my general aversion to using cloud services, I’ve tolerated this one on the basis that my OpenHAB integration doesn’t depend on it.