configure gets all arguments, including the values passed to init. Use the one-liner of my last mail, and you will see that this works for your example as well. if you pass the saved values to object creation, you achieve both, configuring the attributes and calling the constuctor with the saved values.
OK, thanks, this is working for me at the moment.
mixins are in no way more "risky" than a filter or overloading "create". The mixins are in the precedence order before the intrinsic class tree. So, it does not matter whether or not someone has overloaded in the intrinsic class tree "configure", and/or forgotten to write a next there.
Yup, I got confused about the calling order, thinking that mixins are called after the other inheritance chain.