Ok, I found an "experimental" version inside the "interim" folder of the project and seems working with wavepack with Foobar stable branch (v1.4.6). Unfortunately there're trouble with the latest beta (v1.5 beta 14). EDIT: Well, it doesn't work at all. It looks like the plugin is bypassed staying on the bottom in "Playback > Decoding" list so that the default "wavpack" comes in action.
Ok, I found an "experimental" version inside the "interim" folder of the project and seems working with wavepack with Foobar stable branch (v1.4.6). Unfortunately there're trouble with the latest beta (v1.5 beta 14).
I can confirm that there's an issue tagging wavepack files that contain dsd signal when using this plugin. Tagging them via Foobar ("Editable Tags" checked) result in corrupted files/tags that need to be fixed using external editor like mp3tag. If "Editable Tags" is not checked, wavepack files are simply impossible to edit via Foobar. I tried uninstalling "foo_input_sacd" and tagging works just fine. I also noted that when "foo_input_sacd" is installed, if you check a .wv file right clicking on it...