We have a complicated set up for caching state look ups to handle both filtered and full state look ups. However, the eviction strategy is sub-optimal: we keep all cached values for a given state group until we stop querying for any keys in that state group.

This means that if we pull out and cache the full state for a state group, we will keep the full state in the cache even if we only query one type / state key pair periodically.

Ideally the cache would see that nothing has asked for the full state in a while and evict it.