To be honest, I'm not sure offhand why your autogenerated patch isn't working. But looking at that file, the tail end seems autogenerated from armbian/build/patch/kernel/archive/rockchip64-6.18/dt At a glance, if you toss your .dts in that folder, looks like it'll pick it up. Were I to wager, that's probably a newer feature, and possible the documentation hasn't been updated yet. If that's the case, file a bug.
