Adobe DNG Converter has long been a PITA for bulk conversion operations. It didn’t use multiple cores, and it would only convert a 100 or so files before it would abend. I’ve been using the version 184.108.40.206 on the GFX 100 files, and I am happy to report that things have changed. I just converted 500 files in a single batch with no problems, and the program used 16 physical cores quite well.
Thank you, Adobe.