I have another product from Boston (Boston Power Converter USB auf 9V/1A) but since it's output was 1A I purchased this one since it's output is 3A. When I plugged this to a power bank via daisy chain, it couldn't powered 5 pedals under 1A (Boss IR-2, Boss RV-200, Boss JB-2, TC Electronic Polytune 3, and Tc Electronic Mimiq ~675 mAh)
But the Boston one was able to do the job with the same power bank.
With a phone charger + daisy chain it works perfectly, but that is not the use case I want to achieve.