working with system.new.dat

Hello, I have a question about compatibility for this tool with Android Marshmallow 6.x and system.new.dat format of the file. As I understand it's an old way of compressing system image. With tools like sdat2img and img2sdat I managed to convert system.new.dat file to system.img, then repack using afsr and pack back into system.new.dat but I successfully bricked the device without understanding what went wrong. After some investigation, I discovered that the conversion process (system.new.dat → system.img → system.new.dat) can introduce inconsistencies in the transfer list format and block allocation. The original system.transfer.list properly covered the full partition with optimized block ranges, but the one repacked with img2sdat only addressed a subset of the partition blocks, essentially creating a truncated/incomplete system partition. I'm wondering if afsr, on your opinion, is compatible with such android version and the only problem could be the way of conversion .img into .new.dat. Would be grateful for an answer thanks