The majority of the samples in this set have now been tested, and working. I found a work-around for the SD-card reader on the xiao expansion base using the zephyr spi bitbang driver.
The Sd card sample will write testing.txt with the contents “Hello from Xiao nRF54l15” in it to the inserted fat formatted sd card.
I’m not sure why the regular spi driver refuses to initailize with the SDcard reader on the xiao expansion base, but this works so, it’s at least access to sdhc!