according to the definition of Quick Charge 2.0, it should support up to 2A. This is the case with the cable mentioned. It is not excactly hyper-fast charging but the same you get from your regular power supply based on the QC2.0 standard at home. Nevertheless, when used to connect your phone...
I guess this should also work with 6V/2A, the product description of the 'wireless charger cable' says so, however, I used the front port and it works smoothly.
Maybe this might be helpful to achieve what you want:
www.sp-connect.eu/collections/bike/products/cable-wireless-charger
www.sp-connect.eu/collections/bike/products/wireless-charging-module
I got the charging cable from SP Connect fitted by my local Specialized dealer and he saw no...