I admit not doing any research, whereas this bug is found/solved/resolved, anyways:
in the designer (3.1.3.SP1), if you have superstate SS, node N in it, and transition from outside node pointing to SS/N, then if you rename superstate SS to SS1, this transition is not updated to SS1/N.
Additionally, in my view SuperState execute implementation is very weird one - taking the first node and entering it. When first means, the first in DB, which is usually the first in xml, that's very error prone in my view. Why not have something like start-node analog for it?
My use case is to enter this SuperState node on some process event, but now I need to add external Node to enter this SuperState. I cannot rely on sequence of xml entries of course.
Also, putting start-state node into super-state (nonsense of course, but could be done accidentally), and then trying to delete it, throws classcast exception. Not nice.