After installing Finale 25 on El Capital and then installing Dolet 6 with Dolet67FinaleMac.zip, I see the MusicXML submenu in my plugins menu, but when I go to that menu line, no submenu items appear.
BTW, the alias folder for Finale 25 was not there so I found the path and dragged the plugin manually to Macintosh HD/Library/Application Support/MakeMusic/Finale/Plug-ins
Is this a known issue, or do you need more info from me?