I think Blindside can be helpful, as long as you're aware that some feats may take longer if your enemy squads die from "exposure" instead of from your character. I haven't equipped Blindside for that reason, after catching up on those forum concerns and the Developer post on some feats not counting the defeats, with the specific expose example. I don't want to pay to unequip.
Steadfast Focus looks neat (I haven't encountered one yet, or it was a white data disk) and could be helpful for the Overprepared enemy bonus. I'm seconding Scuttle's recommendation. Although I see you've moved on by this point.
I mean, we all need to keep moving if we're going for crate maximization.