The ConfigurableClass can be currently configured to be used globally or in a space, with this definition:
configureGlobally (boolean) - Set this true if your application should be configured in the global administration page and false if it should be configured in the administration page for the space which the application resides in.
So right now the following limitations exist:
1. it's not possible to have a configurable class used at the same time for the global administration AND for space administration pages
2. it's not possible to have a configurable class used for ALL space administration pages, and not only in the space where the configurable class is declared
We should improve the mechanism to be able to use a configurable class for all space and wiki administration pages.