Thanks, I appreciate the corrections and detail. I was mostly going by the committee draft on the arXiv (https://arxiv.org/abs/1908.03565 https://arxiv.org/abs

Thanks, I appreciate the corrections and detail. I was mostly going by the committee draft on the arXiv (https://arxiv.org/abs/1908.03565 https://arxiv.org/abs/1908.03565 ), which still mentioned the quantization constraint (J.3) and a "mathematically lossless" mode (annex O) distinct from modular. "Four formats" was just imprecise wording on my part. The material already public about JPEG XL's design rationale, testing, and so on has been really fun to follow as an outsider. I selfishly hope there's more of it as the work on it and rollout continue. Even with the standard itself public, a lot can be mysterious to those not immersed in this stuff.