Answering your question, yes, Pboost (1 and II) works just fine with P7. And while the multiple runtimes can be used to break up your content, if your want -custom- libraries in one runtime, you need P-booost. And it is easy to create a new library category, then move/copy whatever files you want where you want it. It isn't as indispensable as it was with P4, but it isn't ready to be round filed, either....