I would say don’t bother about converting from Adobe profiles, because it will not work in darktable if you don’t compile darktable/latest lensfun. Adobe has also stopped using TCA correction in its profiles.
There is a development about using Sony EXIF corrections, but not finished yet Manufacturer lens correction module for Darktable
So, what is left is to create a decent Lensfun profile yourself. You have a prime lens, so it will be easy and quick. I have written this Create your own lens correction data for Lensfun – Kameratrollet
There is a VirtualBox with Ubuntu pre-installed with the scripts needed for generating TCA and vignetting profiles. For distortion correction you will need Hugin.
If you want the profile already now you can can just upload raw samples and I can create it for you.
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(Distortion) Three raw files of straight lines, around 8 meters or more away.
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(TCA) One picture of a grey fence at f/8 and also some distance away.
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(Vignetting) You will need a diffuser to put in front of the lens. Take raw samples at f/1.2, f/1.4, f/1.6, f/1.8, f/2, f/2.2 f/2.8, f/3.2, f/3.5, f/4, f/5.6, f/8, f/12, f/16 at focus distances 0,4 meter, 0,8 meter, 2.4 meter and at infinity (focus on objects far away, for example clouds).