[@kersel][@Starlance] He's pretty open with where he's from, he even has an accent and practices Imperial fencing in his free time. In his opinion, it's better to be up front about it so no-one thinks he's trying to hide anything (like Nick Valentine in Fallout 4, about being a synth)

As for when/how long since he defected, he's been around for long enough that they can trust him with military equipment, but he's also been rotated around a lot so he's probably only been assigned to the Wandering Star for a few months...