It's a very small issue but if you turn on the machine with an SD card already inside the reader it stops working until you reboot it once again. This issue is present on an M2 Pro Macbook Pro running Nixos 25.11 with the 6.18.8 kernel, I don't have any other machines that i can test it on. The card reader just acts as if the card didn't exist, no unusual error messages in dmesg. I don't know if this is an m1n1/u-boot issue but i assume its best to put it here.