VEX Electrical Distribution Clarification

I am looking for clarification regarding the electrical distribution system of the VEX systems. I know that motor ports 1-5 share a 4 AMP load, and ports 6-10 share a 4 AMP load both drawing from the main 7.2 V battery. I know that the 4 motor ports on the power expander share a 4 AMP load from its 7.2 V battery.

Please see the attached picture.
My first question is this; if ports 9 and 10 are sent to the expander, my understanding is that their power wire(red) is used as a control wire rather(determining supply voltage) and does not draw current from the Cortex’s battery. Is this in fact how it works?

My second question is this; If that is true, due ports 6,7,8 now have a full 4 AMPS for themselves since 9 and 10 are no longer drawing from it?

My third question is this; if all of that is true, then couldn’t you run ports 5 and 6 to the expander an use y splitters on them to run 4 motors? Wouldn’t that then provide 4 Amps to 1-4, 4 Amps to 7-10, and 4 Amps to 5,6,11,12, with the first two groups drawing from a single battery, and the 5,6,11,12 group drawing from a single battery.

In other words if a single port from each cortex bank(1-5, 6-10) is ran to the expander, would that leave the entire 4 Amps per bank for the remaining four ports on each bank?

I’ve read the wiki and this is what I’ve determined based on that information, I am wondering if it is correct.

I don’t see the picture.
port 10 cannot be sent to the expander, only three wire ports 2 through 9.
The white wire is the control signal, otherwise yes, power comes from the expander battery not the cortex.

see above, 10 cannot be used, otherwise yes.

Yes.

Yes.

See this for some more information (power block diagram in post #1)
https://vexforum.com/t/power-distribution-and-status-display-for-the-cortex/22973/1

Thanks!