Quiver FTW, Caldy has no sustain and a little can go a long way.
I’m a melee player though so I may not give the best advice on a mid-range skirmisher, but if there were an item like that for melee chars I’d consider it. Caldy chases, spams crits, and kills quickly, I don’t see much benefit to preventing shields from recharging when you’re typically doing that by chasing people down and shooting their heads.