A Japanese PS2 coder has released an unofficial version of HDL_Dumb. The app itself is still in English but the change log is in Japanese, so we have no idea what additional features have been added. From what little we have been able to gather, there may be some transfer speed improvements. There definately appears to be an additional preferences dialog in the program as well. Let us know if you find any further details about this.
Thanks to "Haro" for the tip.