Tiny JPEG preview in DNG converter when using JPEG XL

[Edward33272015bool]

I'm invoking DNG converter 16.1 from the command line in Mac OS Sonoma 14.2. When using JPEG XL compression (e.g. with flag -jxl_distance 0.2) I only get a 256x192 pixel preview in the resulting DNG compared with a full-size one without the jxl flag. This seems to me to be a bug, or is there a workaround?

Command is of the form "$dng_converter" -d "$output_folder" -p2 -lossy -jxl_effort 4 -jxl_distance 0.2 /Volumes/Untitled/DCIM/source_file

[Lumigraphics]

What happens when you leave out the preview flag or set it to -p1?

[Edward33272015bool]

The same thing. The preview flag does not affect the outcome.

[Lumigraphics]

How are you getting to the preview? Can you extract it with EXIFTool?

[Edward33272015bool]

Yes I can extract with EXIFTool, and it is used in a number of different image apps such as XnView. This is the main problem, in that all my apps which are used for browsing raw files rely on the embedded jpg which comes out either tiny or very blocky.

[Lumigraphics]

Sounds like a bug.