Right now there is no way to set a default value from a specialization on a property of the generalization.
If one tries to add the same attribute to the list of attributes, an error message is displayed that the attribute is already present, so this also makes it impossible to set the default value.
One option to make this possible is to add an event handler on the specilization that sets the value on creation.
It would be nicer though if it would just be possible to set the default, without the needs of such a work around.
Still only 4 votes? I could really use this!