Looks like you are running with feature caching turned on.  Suggest you turn it off-then we won’t do the unneeded work. You can have your cake and eat it too with a bit of a workaround:  check out https://www.safe.com/blog/2018/05/caching-data-fme-evangelist174/ and https://community.safe.com/s/article/feature-caching-and-performance 

Hint: collapsed bookmarks may be in your future. 

Note that we are looking at ways of solving this issue in a more discoverable fashion. Sorry about the workaround for now. 

All the best.