I wouldn't know since remember my H3 would always put the tv in HDR on regardless so I don't know what it looks like with it off. LG should have something on the remote to manually turn HDR off or on since you don't want some hardware or anything else controlling your picture settings on the tv.
You can turn HDR off on the LG but it has to be done very quickly every time the HDR is on pops up go to it with the LG remote and hit the X to turn it off. Not a good option and it's a pain to even hit it in time before it goes away.