SDK: Krakatoa Interface not recognized

I have a SimpleObject2 plugin that returns an implementation of Krakatoa’s interface.

However, Krakatoa plugins (example: KrakatoaAtmospheric) are unable to select it.

By setting a few breakpoints in my code it seems as though Krak is not filtering by interface, but instead by hard-coded classID (I notice it is able to pick things like pflow and superspray, but not other 3rd party particle systems that implement the IParticleObjectExt interface).

Is this a limitation or am I doing something wrong?