P: Lossless JXL Compression on Mosaic (Greyscale) Data

Lightroom is already performing JXL compression on linear DNGs created from Panorama merges and other linear operations, and it has resulted in amazing space savings. The DNG spec already allows for JPEG92 compression on bayer data and JXL compression could offer an additional ~20% space savings over that. This is especially helpful on very large image files which are becoming more common. 

Lightroom already supports JXL compressed unmosaiced DNG files. Other tools can create them, and Lightroom supports those. Extending the "Create DNG" funtionality to use Lossless JXL would probably be a very user forward feature.