I have a fairly power-hungry laptop I use for work. The laptop uses a lot of power and the dock I have for it actually uses 2 USB-C headers that are magnetically joined to deliver power to the laptop. I plugged my framework into the dual-header connector, and it charges and delivers video to my external monitors, but I am not sure if it takes power from both connectors (the charging light only lights up on one port).
I am guessing that since all 4 expansion ports can act as the charging interface for the computer, that there is a possibility of having multiple power sources for the laptop.