let me try to see if i can submit a patch for the same. One possible solution is to make us provide the runtimeTypeExtension and serverTypeExtension similar to how we have the behaviorExtension so that the extensible adapters can still be considered as their extending parent when packaged together. Not sure how this sounds :-/
back to the customization part, we need to do lot more than just setting of paramter, like validation of the modules before deployement, custom deployment methods and its very specific for our bundle that is configured on top of JBoss.
--Kamesh