There also is a related issue: Currently it is not possible to change the in/outlet count through messages, AFAIK, which hits everyone developing with [pyext] a bit all the time. ;)
a late comment on this (just returned from abroad residency): Setting inlet/outlet count inside the script will most probably become deprecated (because of the mentioned facts). Instead use something like [pyext 2 3 module.class args]
greetings, Thomas