Just got Lathe Worlds.

The section on Integrated Weapons got me thinking about the power armour my Explorator character owns. The first though was integrating the power armour with the potentia coil to overcome the time limit on use.

Following the example of Integrated Weapon Upgrade:

Integrated Armour Upgrade: Weight: +0.5kg, Availability: Extremely Rare.

However, if combined with an MUI, could the integration replicate Black Carapace effect, removing the hulking trait? Would that be reasonable in your view?

FYI, you might want to look at Dragon Scale Armor, from DH - Inquisitor's Handbook.

And you definitely would want the Explorator to get the upgraded Potentia Coil, especially if you are having two high-power-drain items running off of it for long periods of time…

Just looked this up. Pretty much as I wanted.

The question is what availability to put on 'Tech Priest Only'… Is there any consensus on this?

Given the Tech-Priest Only.  I would give it an Extremely Rare, with Peer (Adeptus Mechanicus), Very Rare On a Forge world.  But that's just me.

 i'd be reluctant to put it at anything below Extremely Rare, given where normal power armour is placed, when acquired by an Explorator or other Tech-Priest.

 Yes. Same as normal power armour, but obviously only Tech priests can use it - barring hereteks….