after some serious recursive thinking it now actually makes sense.
The key was to change the actual type of the class that the meta_class manages
For objects it's (still) ok just to change the instance_type, but since the class object exists and has type, when adding instance variables, that actual type has to change
as they are just the type of the meta_class, that was relatively simple.
I feel this is what oo is meant to be, instance variables and methods for the objects, and since classes are objects, for them too.
Class variables seem like a design mistake, weird scoping rules and no data hiding (left as an exercise to the reader)