So far only two types of indexes were supported: the classic street index with a fixed predefined set of additional points of interest added, and the custom map marker index only available via the alternative neighborhood POI frontend.
Soon it will be possible to choose from a variety of different indexes retrieved from the OSM database for different use cases, e.g. the first additional index being a healthcare index showing clinics, doctors, pharmacies etc.
This is all still a bit in flux right now, I had been working on making the index generating code more flexible for quite a while and by now have cleaned up and refactored the code sufficiently to be able to add further indexes rather easily on the Python side of things.
In the long run I’d want to be able to make things even more configurable without even having to touch the Python source code in most cases, by being able to specify what tags to index, how to categorize them, etc. via the configuration file instead.