Ok. I had to manually update cameras.xml shortly after the Z8 came out, and probably missed that the rpm eventually included it. Currently on 4.6.1-2.
As opposed to the HEIF format? I had tried HEIF some time ago but darktable didn’t seem capable of reading those, which I attributed to perhaps proprietary (Nikon) compression. Really have no idea why it didn’t work and simply went with what did work. I have no jpeg included in the camera settings, just raw. Off topic, but I’m curious why darktable (or rawtherapee) is unable to read .NEFX files resulting from pixel shifting (using NX Studio), which I currently attribute to my inability to fathom pixel shifting in these software packages, or my google-fu is lacking.