mcc111[m]: > <@mcc111:matrix.org> I think what I am missing is conceptual/theoretical :(
> 
> Okay so a basic question. When I see "IOT_51A/4.2B" on that port. What "is" that? Is that a single GPIO pin? What on this schematic lead you to the conclusion that the LED anodes should be one 4-bit value and the knodes (cathode nodes?) should be four one-bit values?

It's mostly just convenience that the `aled`s can be specified in one line like that; they're 8 separate pins.