Hi,
I will add some more details about how these flashing stuff works.
You don’t need to care about the command on the document. They are used to flash the whole device (QSPI + SD/NVMe/USB), and since you are only flashing the QSPI, please just use the command I gave you. Moreover, whether it is
sudo ./flash.sh --no-systemimg -c bootloader/generic/cfg/flash_t234_qspi.xml jetson-orin-nano-devkit mmcblk0p1
or
sudo ./flash.sh --no-systemimg -c bootloader/generic/cfg/flash_t234_qspi.xml jetson-orin-nano-devkit mmcblk1p1
(Actually mmcblk1p1 is invalid as the SD card is being recognized as mmc0 on 36.2, while it’s mmc1 on 35.4.1.)
or even
sudo ./flash.sh --no-systemimg -c bootloader/generic/cfg/flash_t234_qspi.xml jetson-orin-nano-devkit nvme0n1p1
Makes no difference. They only matters when you are building a whole system image, and this parameter controls what device is going to be mounted as the rootfs, and is stored in /boot/extlinux/extlinux.conf. For the case of SD card image, this parameter is fixed in the image, and you won’t be able to change it by flashing the QSPI bootloader.
For your second question, the answer is NO. I believe that the case is the same whether SD card is inserted or not.