I've released Mednafen 0.8.1 sources and a binary package for Windows. It has PC-FX emulation working reasonably well, with 2 games not working at all(Battle Heat and Tengai Makyu), and 2 game acting weird(Der Langrisser FX, and Zeroigar during time/score attack mode).
I think Mednafen's PC-FX emulation is slightly better in a few ways(and worse in others, at least ME-FX can run Battle Heat and Tengai Makyu -_-) to the currently released Magic Engine-FX, however...Mednafen requires a real PC-FX BIOS dump, and is also much more CPU intensive, and David Michel and I have been sharing information, so hopefully most of the icky bugs will be fixed for the next MagicEngine-FX release.
Mednafen does have a fairly extensive debugger, though it's not 100% complete...hopefully someone will find it helpful in translating Miraculum.
By the way, what ever happened to FXer? It would be nice to see more PC-FX emulators, open source or not, whose authors I could exchange ideas with(the Xe author seems to be under an NDA).