Update: when I uncheck "save session on logout" in XFCE's settings manager (and then on the logout dialog as well), logout just works fine and instantly. For me, this a valid workaround and the culprit seems to be somewhere inside that session save feature.
Update: when I uncheck "save session on logout" in XFCE's settings manager (and then on the logout dialog as well), logout just works fine and instantly. For me, this a valid workaround and the culprit seems to be somewhere inside that session save feature.