As a workaround for now I would recommend to add extra/sssad to your
Pd search path in the traditional way: "-path .../extra/sssad" and then use [sssad] as object name. (I don't think, much is gained by having to include a prefix like "sssad/" to a library that just includes a single classname anyway.)<<
that still doesn't work here.
moving sssad and the associated files out of the enclosing folder, directly into the extra folder doesn't help either.
this is reallly making me sssad ;.(