As per the advice of the devoloper of the custom collections used in my data-source (LLBLGen.com):
Their grid should call ITypedList's GetItemProperties on the datasource bound, and work with the IBindingList properties for grid behavior like sorting.
They should obey a 'Designer' attribute on the bound datasource as well; as the minimum a 3rd party control should be able to do is what the vanilla MS controls are able to do.
I hope this helps in making FlyGrid more useful for business-objects devolopers.