Wow, that's impressive for one or few hours of work and an update would be great! HD Reworked Project is the toughest one to extract uncookable textures from, especially since tree DDS-only textures, which cannot be imported as TGA's/cooked as XBM's, extracted from texture.cache with Cache Reader are of lower quality and file size than the ones used for cooking. The only trick that I know of to extract full quality tree DDS-only files from incorrectly cooked mod is to create a properly cooked (uncookable) DDS-only mod with bundle file using vanilla files, then replace custom mod's bundle and metadata files with vanilla mod's bundle and metadata files. That uncooks full quality DDS files 90% of the time, but that does not work for all mods. Some textures end up corrupt or un-openable, look corrupt in the game if recooked, yet work perfectly fine if left in original mod's texture.cache. Sometimes I see unreadable symbols in texture.cache and Cache Reader usually crashes upon extraction of any files from such texture.cache files.
Non-tree DDS files (normally in TGA/XBM format) from texture.cache seem to be of full quality, but of course they have to be converted to TGA and imported/cooked.