I would like to see Darktable backported from testing as well. Currently I am using Sid backport from FastForward repo.
❯ dpkg --list | grep darktable ii darktable 5.4.1-1~ffwd13+u1
OpenPGP_0x193A6B9C20DCC436.asc
Description: OpenPGP public key
OpenPGP_signature.asc
Description: OpenPGP digital signature
