You seem to play a lot with inverter. I rarely get time. For me its fit & forget. Sukam guys comes every 6 months to check water level & top up.
As long as it runs 2 fans, 2 lights, 1 LCD, 1 laptop & Wifi. I am fine. I am not into load testing
I wonder if 850 VA can run so many things like you said - quad core pc , 32 in lcd, 5 tubelight, 4 fan, 2 cfl.
Why run a donkey in the race when its already walking fine. Donkeys are not for race, one needs horse