It could add an extra layer, and alternative, to genetic mutations. Cybernetic limbs could be a replacement for limbs if they are torn/bitten/blown off in a chance when being reduced to critical condition. Arms could give increased melee damage, legs could make you faster, etc.
New faction that has an alternative view to how the Church Of The Husk strives to survive the depths? While I love the Children Of The Honkmother, they don't really have too much of an opposing philosophy compared to the very relatable political ideologies of the Separatists & Coalition, as they are polar opposites.
Possible inspiration from Caves of Cud or 40k: Mechanicus, the latter especially fits the atmosphere of barotrauma perfectly.
Take control of one of the most technologically advanced armies in the Imperium - The Adeptus Mechanicus. As Magos Dominus Faustinius, you’ll lead the expedition on the newly rediscovered planet of Silva Tenebris. Manage resources, discover long-forgotten tech, plan tactical operations using the Noosphere technology and control your Tech-Priests...
