So, I purchased this item as a bit of a gamble to use with a JxySolar 25W flexible solar panel that does support QC3 but not PD. only had a 5 minute test in early morning sun, but plugged it in the 5521 socket, and it started charging at 9V 2A (18W) straight away, no questions asked (tested with a usb volt meter) tested on a phone that maxes out at 18W PD. will test further with other loads, and feed back more when I get a better chance to test out further.
after further testing, I've successfully charged a couple of powerbanks and hit a peak of 12V2A out out of a 25W solar panel, I couldn't ask for any more :) brilliant bit of kit for the task at hand