The full rules proposal for warcaster armour upgrades can be found in the Gearbooks II PDF.
Mindshadow Override
[Warcaster Armour Upgrade]
Cost: 300 gc
Effect: While a suit of warcaster armour fitted with a mindshadow override is running at full steam, steamjacks in the warcaster’s battlegroup do not suffer backlash or become autonomous when the warcaster is rendered unconscious (see IKRPG, p. 324, for backlash rules), but continue to enact their warcaster’s will as long as the warcaster remains alive (i.e. the steamjacks will act with as much intelligence and tactical awareness as if the warcaster was still conscious – in game terms, the warcaster’s player keeps directing their steamjacks, which keep activating on the initiative result initially rolled for the warcaster).
If the suit of warcaster armour becomes unpowered or set to run at low steam while the warcaster is still unconscious, or if the warcaster dies, all steamjacks in their battlegroup immediately suffer backlash as normal.
Steamjacks still cannot be allocated focus or get powered up by being in the Control Area of a warcaster of at least Veteran level while the warcaster is unsconscious, but they can receive focus from other sources normally (e.g. the Power Booster spell in IKRPG, p. 242).
Power Requirement: 2
Installation: Installing a mindshadow override requires one hour of labour followed by a successful INT+Mechanikal Engineering roll against a target number of 14.
Fabrication: The material cost of the mindshadow override’s parts is 50 gc. It takes two weeks to construct the device. Fabricating a mindshadow override requires the Inscribe Formulae ability as well as a successful INT+Mechanikal Engineering roll against a target number of 14.
Comments welcome, as usual.