Currently JNILibLoaderBase uses classloaders only to look for .so libraries (and only system classloader). It should use classloader to look for a packed .jar version too and try to use thread's classloader to look for an .so. At the moment it tries only fixed path to jar, relative to application basepath.
No it should not, this class is dedicated to load native libraries utilizing many diff. strategies. TempJarCache's find*() methods match ClassLoader's interface and can be utilized in a custom CL, as mention in IRC already.