USB-C PD, 14.5W x 2A, 29W
Standard Qi wireless, 5V x 1A, 5W
Compatible Fast Qi wireless, 5V x 1.5A, 7.5W
Given the wattage options, it’s a no-brainer to enjoy the speed of USB-C wired charging.
I have a 2015 MacBook, so I already have a couple of the 29W USB-C adapters, but the 2M USB-C to Lightning cable was both sold out and overpriced, so I ended up with this one, and it works well with Fast Charging as of iOS 11.2.6:
Fast Charging USB C Lightning Cable, Ofspower 6FT Nylon Braided USB Type C to USB Lightning Syncing and Charging Cord for iPhone X, 8, 8plus(Gray) https://www.amazon.com/dp/B077TQSSQP/ref=cm_sw_r_cp_api_en7PAbZVGKW87