This is my first venture into DSLR scanning. Or a mirrorless XT-4 with attached Vivitar 55mm f/2.8 Macro lens, in my case. Edited in RawTherapee 5.8. It wasn't a quick process, but I showed that it could be done using FOSS photo editing applications. And it didn't hurt to have the grain elevator in the background as a neutral gray point. I have a few other photos from this roll that I did, but this is the best one.
Scanning like this offers some incredible results, but it's not without some challenges. Specifically, getting white balance and all the colors just right can be tedious if you don't have the right tools. Apparently there are some plugins for Lightroom that make this dead simple. However, I don't use LR simply because I refuse to pay Adobe $20 a month for the privilege. So, I will continue to refine my workflow with RawTherapee and hopefully the processing time will improve over time. Moving forward, I intend for all of my scans to be done this way.