dont wait for india update. go to friza tool and download the firmware of your device from German and flash throgh odin. thats it. I am presently running the latest version from German firware version E6 in my s20 ultra.
absoluyely no problem. because odin is almost official tool and no warranty will void neither knox will trip. the firmwares are all multilingual and so no problem and also you will receive ota for ur region. See i cannot say about improvement. because from the day one i am using this firmware because i received my unit after 17th of this month and from day one i am using the **bleep** firmware of my device.