Thread:Extension talk:CirrusSearch/Multi namespace suggest

I recently installed cirrussearch and am trying to figure out how to get search suggestions from multiple namespaces. Here's an example using Main and Category; type 'air' and get suggestions for 'airman', 'air density', but also 'Category:Airplanes'.

I've appropriately configured $wgNamespacesToBeSearchedDefault, but this doesn't seem to affect suggestions the same as it does search results. Is there anything else that needs to be configured?