The buffer visualisation looks correct as you are using post process effects.
Therefore Unreal Engine provides a optional post processing pass that attempt to fix this issue using a Panini While applying your panini you’ll see that with buffer visualisation even the individual buffer viewports are distorted as the effect is applied after and to your complete viewport.
The MRQ neglects the effect while rendering your depth with the post process material (probably on purpose as any other post process effect would affect your depth anyways - didn’t look up the source). So what you would need to do would be to apply the same math in your DepthJo pp Material. For panini you could use this tutorial and the shader for your scene as well as for the depth UE4 Tutorial: Panini Projection - YouTube
Same goes for the tutorial from @3dRaven. The code should go into the DepthJo as well. Why your beauty is black in the sequence is probably something else to look at if you use the tutorial.