Not sure have this been asked before

On V12, I no longer able to change the bit rate to what I wish to use as before when render to MPG4 using Maincoept AVC/AAC. I only see option for bit rate of 2M, 4M, 10M etc. I always use 6M or 8M to render out MPG4 video for my client. Has this feature been turned off by Sony?

You can write any digits for bitrate in VBR mode

Same here. Don't use the menu, just type in the bitrate you want.