The only working dtb I have is from 3.x kernels yes. But I have no clue how to make that work for 4.x/5.x kernels or how to fix the non working p281 thats bundled with the new builds. I also don't know how to build 3.x kernels from source, by default the s905 build now builds a 5.x kernel. Not all modules I need are in 3.x kernels and also some wifi drivers don't build or work good for 3.x. They're usually for 4.x or newer kernels.