How to configure the set of grains that a silo is allowed to activate

[LawrenceWard]

I have a certain grain type that I want to activate exclusively on configured silos, and those silos would also exclusively activate this grain type. If possible I want to achieve this purely by controlling the grain manifests of each silo. I don't want to change or use placement strategies or silo roles. I want to affect the list of silos that are returned by IPlacementContext.GetCompatibleSilos(). It looks that I could probably achieve this by configuring TypeManifestOption.AllowedTypes to remove grain types that I don't want to active on each silo, but I don't know where, when or how. What should I do?

[LawrenceWard]

Ok, I was able to do this by using services.PostConfigure<TypeManifestOptions>() to trim Interfaces and InterfaceImplementations.