Hey @borrowmayo ,
They way it works is that in case of hybrid directory, it will only delegate to underlying MMapDirectory based on index.store.hybrid.mmap.extensions (which in turn, has preload configured based on index.store.preload). So if index.store.preload is a superset (to clarify the case - it has all of index.store.hybrid.mmap.extensions + some more), the other extensions won’t be used for hybrid directory.