Hi Paul
I haven't noticed any difference wether it's ON or Off
However, i found out another way to solve this problem,
Now i don't know how you do most of your TV watching but i do mine mostly watching regular HD cable programing
I also watch a lot of Blurays and some 4K streaming via wifi.
So the only thing i had not checked yet was the settings of my cable box.
When a purchassed my E6, i had to get the 4K cable box that my cable provider offers to get the ''4K experience'' as they say...
So i checked the settings of this cable box to found out that the TV picture resolution signal was set to 1080i
I changed it to UHD 4K and see what would happen. I then returned in my Marantz settings and change the settings in Video - Output Settings as this:
For Marantz model NR1606 paired with LG OLED65E6P
Video Mode - Auto
Video Conversion - On
i/p Scaler - HDMI
-Resolution (analog) is grayed out on Auto
-Resolution (HDMI) - 4K
-Progressive Mode - Auto
-Aspect Ratio - 16:9
Guess what my friend ? the picture became better then i ever expected

I watched part of the semi finals of the World Junior Hochey Tournement on TSN 4K and the picture was absolutly amazing ! no blur, no judding just crisp and clear wow picture.
All the other regular HD chanels looked great as well and close to 4K. It must be the upscaling factor.
I really hope this will help some owners of this wonderfull TV because it really has the best picture i've ever seen.
Finally, here are my favorite settings used for most of my viewing wether it's cable TV, Bluray of wifi Streaming :
Picture Mode:
HDR Effect (User) Medium
OLED LIGHT:
60
Contrast:
89
Brightness:
57
Sharpness:
10
Color (grayed out)
50
Tint:
0
Color Temperature:
W35
-
Advenced Controls
Dynamic Contrast (grayes out)
Off
Dynimic Color
Off
Prefferred Color: Skin Color at 1, Grass at 0 and Sky at 0
Color Gamut:
Normal
Super Resolution
Off
Gamma (grayed out)
Medium
-
Picture Options
Noise Reduction:
Off
MPEG Noise Reduction:
Off
Black Level:
Low
Real Cinema (grayed out)
On
Motion Eye Care:
Off
TruMotion (User):
De-Judder at 4 and De-Blur at 10
---
Aspect Ratio:
Original (Just Scan)
3D Settings to your choice
Dual Play to your choice
Energy Saving:
Off
Eye Comfort Mode:Off
---
OLED Panel Settings should have Screen Shift ON
I hope this will help
Please give me your feed back.
Frank (meg1st)