There is still a bit more development to do on it to get the last bits working, but it would be useful to have somebody else looking at it and testing it (plus there are still some things I havent worked out a plan for yet). After that I will work on making the process easier for others, but up until now you need to program the chip (Wemos D1 R2) through Arduino Studio (as you need to change things like WiFi keys), after changing the main settings you just connect the cable to your Powermax.
Do you have a usable chip to hand? Can do it via PM or keep the chat on-thread in case others want it.