I am not a developer. I create this thread hoping those knowledgeable people will notice this rather cheap yet with good hardware router. It’s based on MT7981B.
You can find some things without opening the device.
Firmware encrypted...
Search GPL sources from OEM if any
try this TP Link firmware decryption
Then binwalk (-eM) to find DTB file, chop it out with dd
Then use dtc to convert it to dts.