I tested the higher power consumption by using USB-A on port 1 and 3 and USB-C on port 2 and 4. I plugged in the receiver of a wireless mouse on 3 and an electric bug zapper (5V input, rechargeable) on port 1. I shut down the computer and unplugged the adapter. The charging light went off after 20 seconds, indicating the power to the port switched off. After 24 hours of off, I turned the laptop back on and the power went from 80% to 78%.
In conclusion, using USB-A on port 1 and 3 does not increase power consumption when the computer is off.
The answer is part of USB-C but in a very weird manner, see below.
Eureka moment: I found the culprit. It’s the USB-C PD negotiation.
When powered off, the USB-A expansion cards negotiate PD from the mainboard(all ports for expansion cards are USB-C) only once so it’s not a problem.
However, if you plug in a USB-C device into a USB-C expansion card, it’ll try to negotiate USB-C and the USB-C card will power on regardless of which port you are using. To make matters worse, this negotiation turns on all four ports, increasing power usage from these USB-A as well.
I tested by shutting down the computer and waiting for a minute, then I plugged in a smartphone to an USB-C port. The phone showed charging AND the charging light from the USB-A bug zapper illuminated.
Hope this is the answer you @hitech95 are looking for regarding why the Framework 13 drains battery while powered off.