There is an ongoing beta test in a small group of local testers in China. I've planned to include some foreign users. But it's been canceled due to the shipping issues. You may have heard from me about the beta tests, I'm sorry for not keeping my word on that. The good news is so far no serious problems found in the beta tests. Thus, the release version would be ready for sale in about a week. Check my website for its availability.
So far the adapter supports all the Contax 645 lens including Mutar 1.4x. However, only part of them, i.e. 35, 45, 80 and 140, can AF on GFX50s. Don't ask me why not adding the others to the AF list. You don't understand how difficult it is to make a lens designed for a SLR decades ago AF on a CDAF only body. Thank god at least I succeeded on some of them. 4 is better than none, right? And MF is not a big problem I guess. The aperture control is. Now all the C645 lenses' aperture can be controlled electronically by the aperture ring of the lens or command dial of the body.
GFX's mount does not have an open design. I don't think Fujifilm expects the third parties to develop smart adapters for it. Thus, there are limitations and compromises. Read the user's manual before considering this adapter product.
Thanks to Mr. Antunes who took the following sample photos.
Contax 645 80/2