Transcode a video in Yuv 4:4:4 high bitrate

[Kristop]

Hi,
I am trying to convert videos with a very high bitrate (between 100 et 450Mbps). They are coded in Yuv Planar 4:4:4, Yuv444p (I repeat this for the search tool of this forum which requires 6 letters!).
I have some problems:
- I cannot set the bitrate or the quality for the mp4/H264 codec in the convert interface: it says "not used", accepts a number input, but resets it when leaving this field
- Sometimes, it accepts a number, for instance 29000kpbs, but the final result is ... around 300kbps!
- I tried also in avi/H264, it accepts a bitrate value, but... always end up using something around 2000kbps (tried also the quality value, 10 or 50 does the same)
- maybe custom options could help me, but couldn't find the syntax.

Also tried to use a command line, hoping the bitrate would be taken into account but I need help to format that command line !!:
- I have this command line in a .bat file in the videos directory, but it does nothing (opens and shuts immediatly): vlc -vvv FILE_NAME.mp4 --sout '#transcode{vcodec=h264,vb=29000}:standard{access=file,mux=ts,dst=tmp.mp4}
- also wanted to try that one, but didn't succeed (I removed sacle and audio and channels; mux should be ?):
for %%a in (*.FILE_EXT) do cmd /c "PATH_TO_VLC" --no-repeat --no-loop -I dummy -vv %%a --sout=#transcode{vcodec=VIDEO_CODEC,vb=VIDEO_BITRATE,scale=1,acodec=AUDIO_CODEC,ab=AUDIO_BITRATE,channels=6}:standard{access=file,mux=MUXER,dst=%%a.OUTPUT_EXT} vlc://quit

More context:
- Windows 7 pro 64bits
- or W10 64b on a 2pro Intel Weon E5-2643 V3 @3.40GHz with a Quadro P6000
- I tried these version of VLC: 2.2.4, 2.2.6, 3.0.0-git, and 3.0.7 today's download