Nice catch !!! With both the microSD and USB key newly written and plugged at the same time in the box, I could successfully boot and obtain the Armbian Desktop. This with the default provided dtb. However without surprise, no BT, no WIFI. I tried the other provided dtb's, some boot with the same result, some don't boot at all.
And with my extracted android t9 dtb, I still have the same result as before: the box doesn't boot.