@Karim
Yes 3x3 and 1x3 is about line skipping in sensor.
Doing Dual ISO after the Binning process it will show a lot of artifacts and aliasing here will come the big benefit of 1x3 mode applying Dual ISO in full sensor height (using more pixels for dual iso) then stretching it down to the correct aspect ratio. In this way the details will be restored with less aliasing and less noise too.
In MLVApp there are no problems when using Dual ISO with
And you can speak Arabic you are from Egypt? I am from Syria nice to meet you here in the forum 
أهلاا و سهلاا
Nice to meet you too Bilal

أهلا وسهلا بيك يا بلال و مبسوط جداً من ابحاثك و تجاربك فى الكاميرا انت عبقري

I was confused about 1x3 and 3x3 but I think I started to catch it right
I tried MLVapp v1.2 and it gave me stable dual iso results, not like the crappy test I made on v1.0
but still, I got minor artifacts like red and white dots it appears like for 1 frame long.
I shooted a 10-sec video and I spotted like 7 or 10 dots in total that appear and disappear instantly
I tried to mess with some setting in mlv app dots almost gone like 1 or 2 dots
It was 14bit lossless 30fps out of 6d
I used:
in details panel
Denoise window 3x3
strength: 35
export settings
prores4444
ffmpeg kostya
LMMSE
resize 1920x1080 (was 1824x1026)
smooth aliasing tried off, 1 pass , 3 pass
seems like 3 pass was softest image but no small dots also less aliasing (straight lines still looks like a zigzag)
Sorry if it's not even related to your 700d research I just wanna to share with you my experience to know if its common or im having trouble in my raw mlv workflow, I feel that I can't rely on it in serious projects yet