This. Sucks. Benson Leung, the Google man who has been on a mission to debunk every faulty and non-compliant and wannabe USB Type-C cable and adapter sold on Amazon, has spoken rather harshly about two of this year's flagship Android devices: the HTC 10 and the LG G5.
Benson actually explained this issue in detail back in November of last year, citing the USB Type-C specification, which forbids proprietary charging methods from changing Vbus above 5V. And you guessed it, this is exactly how Qualcomm's QuickCharge 3.0 works: it can charge intermittently at 9V and 12V to achieve faster charging rates.
So any device that uses QC3.0 is essentially going against the USB-C spec, and that includes our new dear HTC 10 and LG G5 (or not so dear, if you're named David Ruddock).These, and any charger you see that supports QC3.0 over USB Type-C, might be QC3.0 certified but they're not following the USB-C spec.
There is no telling what exactly are the risks, and whether there are any to begin with. USB Type-C has been tested with non-proprietary charging that tops at 5V and found safe and appropriate within those constraints. Pushing that voltage limit might turn out to be OK, but it might also damage your charger and device. It's news like this that makes me thankful for my Galaxy S7 Edge. Until this whole Type-C spec mess is clearer, Type-A works just fine for now, thankyouverymuch.