I swear Missy just likes to mess with us!
So, for the last few chapters I think I've had Dev figured out. I think that she's one of a kind because she really is human, not a bio alt, but she's been "modified" to be able to receive the downloads - but this is why she's able to think, feel and act like a person. But now in chapter 20 one of the characters has put that thought in Jess's mind and I'm pretty sure Missy's done that to throw my theory off!
I had many other theories about what was going to happen but she's completely blown them all out the water with the attack on the base and them now going off to get their own back.