Idea for better JPEG decoding

[phillipseamore]

Noticed this comment from user JyrkiAlakuijala on HN:

Also good to know that Jpegli (a traditional jpeg codec within libjxl) allows for 16 bit input and 
output for '8-bit jpegs' and can deliver about ~12 bits of dynamics for the slowest gradients
and ~10.5 bits for the usual photographs.

Jpegli improves existing jpeg images by about 8 % by doing decoding more precisely.

[...]
Jpegli is predicted to be production ready in April or so, but can be benchmarked already.

And thought it might be interesting exploring (when Jpegli is production ready) the option of doing decoding with Jpegli before re-compressing images to squeeze out a little more image quality.