In the meantime, DAC seems to have been implemented upstream; cf.
https://github.com/etemesi254/zune-image/issues/318 and
https://github.com/etemesi254/zune-image/pull/373. Unless already happened
(which I don't see in the changelogs of loupe and glycin-loaders), I wonder
whether I could kindly ask you to prepare a package (or packages if more than
one needs to be changed) for the experimental repository so that I (and,
hopefully, other users) could test it. I'd test the user viewers `loupe` and
`eog`. There is no rush, and, unless you object, I would be happy to re-open
#1127449, as the circumstances have changed (cf. “until it is fixed upstream”
above).