Also try Scene: Game: Original with Backlight 5, Picture MAX, Color/Bright 50, everything OFF except Dynamic LED to see the "raw" picture. This should be the most lag-free experience, but when I switch between General: Standard and Game: Original, I just love the XReality picture too much. I do not notice a difference in lag but there must be a little; turning Xreality engine ON causes the audio to resync so it must affect display speed.
For me, flashlighting is terrible with Dyanmic LED OFF. A black screen looks like an inverted Rorschach test. :P Setting it to LOW makes the screen brighter and more uniform, but there is very slight backlight bleed in the corners. This is only visible on black screens. Dynamic LED Standard removes all traces of backlight bleed, but at the cost of overall picture brightness. However, I am using fairly high backlight settings (5/6, all ECO off), and turning Power Saver or Light Sensor on does reduce the flashlights significantly, also at the cost of brightness. Something I tried tonight with good results: Motionflow Clear, Backlight MAX, Dynamic LED LOW. Picture is super bright and clear without visible backlight bleed.
I really would like to know exactly what each Motionflow setting does, and each Cinemotion setting too.