I was recently looking in Darktable, Rawtherapee, and ART for the Sony A7c camera and kit lens but I don’t see that listed in the camera and lens calibration lists of any of these 3 programs. Then I notices that I did not see the A7M3 listed either. These are the most recent versions from GIT. Did I miss something?
All three of those applications use Lensfun, and lensfun doesn’t get lens correction support until a user submits it.
RawTherapee and ART can also use an LCP if you can track one down, and lensfun can also convert an LCP for personal use.
So its either sitting in the lensfun queue or nobody has done the work yet.