Short answer: Yes and No. As long as the settings is validated, it should work. If not, then it won't (I realize that this is a bit superficial since there is no standard to validate against yet (well, technically it's there, just not cod-ified yet)

Long answer: Yes and No. My understand is that MXBean uses a similar version of Java boxing mechanism to turn Object into CompositeData. I haven't got around to verify all the possibility yet, but from my limited experience with boxing/unboxing, it doesn't work all the time.