Maybe we also need to prevent issuing queries before we have at least 2-3 characters?
I think debouncing is indeed important so we don't issue too many queries. Waiting for 300ms should do the trick I think.
Perhaps we also need an upper limit on the number of hits? I suppose it leads to poor usability if not handled in the visualization, but we can set it to a high value of e.g. 1000 (which will only matter if there is a reason to autocomplete in the global addressbook where we have lots of entries).