We have worked on the platform and added additional, reusable MPS utilities:

• Targer Chooser: A dialog to choose nodes in a model, typically when trying select a location where to put something in a refactoring or intention
• Selection Intentions: Intentions that can be used with more than one node at a time
• Model Listeners: A listener that reacts to changes (children added or removed) in a model

Check them out on the master branch; they will be in the next platform release as well.