Backplane pinout

my driver is going to have a backplane and im not quite shure how to do the pinmapping on it im using 120p PCI connector and xt60 for DC bus.

In the attached picture you an see the layout i came up with.
But effectively everything is double and i have every pin of every device on the backplane wich is quite crowded.
I think i only need the mcu GPIO on the backplane, and a SPI bus and i2c for internal communication.
i think this question is especialy for @Roiki and @Valentine but any input is apreciated.
as always thanks for the help.

I honestly don’t think you’d need all that io broken out. Unless you actually plan to use them for something.

You could cut them and switch to a board to board connector that handles both power and signals. Makes for easier assembly too.