Olle P :
Overall a nice in-depth review!
Two oddities though:
1. This is NOT a 10Ah battery pack. Since the cells are connected in series it's just 3,3Ah.
2. The ripple is measured at ~9V. Shouldn't the USB output be 5.0V?
Most power banks report the total combined rating of their lithium cells. Travel restrictions don't care if the cells are in series or parallel, all they care about is the total Wh or Ah capacity of the underlying cells. For the end-users, 50Wh is 50Wh regardless of series or parallel as well. When you buy a 5.2Ah power bank, you usually find a pair of 2600mAh cells in parallel but this only gives you ~4V, so you need a boost converter to get that up to ~5.1V. Since the PB06's battery voltage is 12.6V, it uses a buck regulator to bring that down to 5V or 9V instead.
I suppose I should have tested at 5V too instead of 9V Quick Charge. Same inductor and switching frequency though since all the QC voltage selection chip does is change the switching regulator's feedback voltage divider, so ripples would still be quite significant at about half as much.