Your C7 I assume is a post ULSD designed engine. If so, then it is designed to run with this fuel.
So additives for specialty reasons (winter storage, solving a problem from contamination, more power for extended hill climbing or heavy pulling, etc.) is all that is needed.
We have an engined designed for pre ULSD. I run OptiLube in every tank. Usually Summer Blend, which has had improvements since the above linked click study. We also well Amsoil Cetane if we know we're climbing mountains for extended periods.
I add Biobor JF if storing parking for longer periods in high humidity areas.
And we travel with extra filters and Power Services special products in case we pick up a bad batch of fuel.
Best to all, be safe, have fun,
Smitty