OP:
Congrats on the Equinox! Here's the thing about using any additive on a brand new vehicle. There is the remote possibility that your new engine has some kind of mechanical defect in it. Who knows what the actual odds are - very low - but we'd all have to agree there is the remote possibility.
That said, should your vehicle be one of the very few to have an engine failure, it is my belief that it is SOP for a new car dealership to perform an oil analysis on any engine requiring major repair or replacement. In the warranty evaluation process it is my belief that they have an oil "signature" that is used to compare against the oil that came out of the faulty engine.
Should there be significant deviation from the signature they have on file - which any oil additive would cause - it is my opinion that this could compromise the warranty and how those costs are accounted for.
I'll be upfront, I am not an additive kind of guy so I'm not sure what you expect to gain from adding an additive to the oil of a nearly new vehicle, of which you are already running a high quality OEM approved oil. But if you insist on using an additive, I'd wait until 15,000 miles before doing so. If your engine lasts that long it is most certainly defect free.
Scott