It does speed up after sending to background. Maybe that follower count is taking up too much space?
Discussion
Follow counts (downloading follow lists to and from the user in question) can easily occupy 150MB of memory by themselves alone. Then add all the zaps and the situation gets worse. It's very heavy. I am working on a local database to simplify this but it's taking it's time.
maybe nostrdb would work? It's written in c