As noted, there are rules in the Central Supply Catalogue for combining various bits of armour.
The one thing I would note is that before this was published, some bits of armour (like the Protec Suit in Mercenary) were specifically stated as 'can be worn under other armour'.
Items like this, and things like Subdermal Armour implants, should still apply their full armour - they're explicitely designed to be layered with other things.
The one thing I would note is that before this was published, some bits of armour (like the Protec Suit in Mercenary) were specifically stated as 'can be worn under other armour'.
Items like this, and things like Subdermal Armour implants, should still apply their full armour - they're explicitely designed to be layered with other things.