What do you mean Missing? They are certainly there in current Stable. But in any case the 400 is default and the issue with the IMU mask is fixed. So, the default settings for these parameters is correct.
I have a pixhawk 1 using Ardupolit Rover firmware 4.0. I have the same isssue of bad Gyro Health and not able to change to any auto mode. I apply you parameters setting with no change. Does this apply to Rover Firmware? What is the answer to solve this issue?