hello markus.gruber4,
if you’re using flash commands, it’ll update kernel-dtb partition to overwrite device tree binary.
there’re different ways to load device tree,
for example, (1) device tree could load from kernel-dtb partition, or (2) according to post #3, it’s also CBoot feature to look extlinux.conf configuration file for loading binaries. you may specify FDT entry to include the name of the device tree binary file.
thanks