Assuming, of course, that the aforementioned alternatives don't just work with similar or even the very same systems (broadly categorised as Mind Interface Units).

It's probably safe to say that anyone's body put into a machine would lose their "unaugmented" status as part of the procedure.

I'm surprised no one has brought up Black Library character Inquisitor Ravenor as an example. He's grievously wounded, entombed in a life support sarcophagus within an armed and armoured transport device. His is a hover vehicle rather than a walker, but many of the principles are the same.

I'm surprised no one has brought up Black Library character Inquisitor Ravenor as an example. He's grievously wounded, entombed in a life support sarcophagus within an armed and armoured transport device. His is a hover vehicle rather than a walker, but many of the principles are the same.

Although Ravenor was a psyker with mindbending capabilities. As his mind could "see" his surroundings, the whole mental breakdown risk could be considered minimal. Not so sure if you put a standard guardsman in such a coffin...

Any such person should be selected for mental toughness as well. Our Magos is actually looking at making the Thallax conversion less mentally damaging by limiting the sensory input to more 'human' levels and installing pain blocking implants to reduce the pain of the conversion. One of the reasons that they go so crazy is that their 'Djinn Sight' is so very different that they don't percieve the world the same way. He is also looking into using Janus Simulacura bodies as 'Rest and Recuperation bodies' The idea is that the Thallax (or 'Dreadnaught') spends some down time in a near-human body regularly to reduce mental instability. The Thallax and the Janus Simulacura are both mechanical bodies needing only the brain and some spine.

Note that you could put less valuable people in Janus Simulacura bodies rather than Dreadnaughts. They would still be mechanical, but you could adjust the bodies cybernetics to allow some near-human feeling and reduce the mental trauma. They would still be fully functional and quite a bit tougher than human troops.