So...
I use both Concealed Weapon and Cloak on both bars.
Cloak, it's not about the passive perks from it, but the invisibility. Useful for PvE, not necessarily PvP.
Concealed Weapon however is purely for the Passive Minor Expedition at all times, without wasting an item set for it.
I'd love if Concealed Weapon was modified to on either bar, not just active bar, then I could plant it on backbar and use a better ability on my active bar.
Like Puncture, or Mark Target.