Does anybody know what the difference between  HD, Normal and Smooth settings in the RC Transmitted Quality menu???

Not yet, but looking forward to find out!

DJI,  please write a wiki for this stuff !  or " Live" manual    update a few pages at the back, for some explanations of each of the options/features,  to include what increasing or decreasing values do to that option too,    PLEASE  PLEASE PLEASE !

MikeQView Posted at 2017-4-22 06:46
DJI,  please write a wiki for this stuff !  or " Live" manual    update a few pages at the back, for some explanations of each of the options/features,  to include what increasing or decreasing values do to that option too,    PLEASE  PLEASE PLEASE !

Good Idea, it would be perfect.

I wonder if that cooresponds to "Gentle,  Normal,  and Sport" but in reverse somehow in Russian.

I've contacted with the DJI online support and girl in the chat also can't aswer to this question because she doesn't know!!! DJI what's going on?????

It basically adjusts your video downlink bitrate.
If you have it in HD or Smooth, and you're recording in 4k it will automatically switch it to 1080.