Update. This is what I did. Got a fresh set of Exide to replace the old set of Exide.Having said that I think I'm just going to get new set of batteries this time and postpon the decision to 2025.
This time I have kept the UPS on its side and that'll result in batteries staying upright. I'm going to make my UPS even more holy for better ventilation. It's going to be ... Saint APC.