Thanks for the sample, this is indeed getting interesting! This is now a brand new Adobe DNG 1.7 spec file that has an additional subimage embedded inside (rather than saving it as the primary image after enhancement like the other tools seem to do):
[SubIFD1] SubfileType : Enhanced image data
[SubIFD1] ImageWidth : 5496
[SubIFD1] ImageHeight : 3670
[SubIFD1] BitsPerSample : 16 16 16
[SubIFD1] Compression : JPEG XL
[SubIFD1] PhotometricInterpretation : Linear Raw
Note also the very new JPEG XL compression used, which is not supported widely either, so I guess it’ll be some time until this gets implemented by 3rd parties…
Can you please also upload a sample to https://raw.pixls.us/ directly (incl. a note it is the DNG 1.7 w/ JPEG XL compression)?