Flushing and closing connection with HTTP Response acitivity

I have a feeling that http connection is closed/flushed only when workflow instance is finished or suspended.
I have workflow which has HTTP Response activity near beginning then some "lengthier" processing and then it finisheds.

And in browser I see HTTP Response text immediately but the page keeps "loading" till the workflow instance is finished, only then it stops.

This probably happens because of chunked content encoding or something about that.....

Are HTTP Response blocks envisioned so there could be two? So both responses are "concatenated"?
If yes then we need to be able to mark last one so it gets "flushed".
If not (the way I'd want it to be) then content should be "flushed" immediately with first one.