Thanks, altering via pause/update/resume is OK, at least for now. Will try it on practice.
Just in case - question was inspired by Apache NiFi. If you haven't seen this https://www.youtube.com/watch?v=sQCgtCoZyFQ - at 29:10. I would say such thing is a must have feature in "production" where stoppage of processing of live stream is not acceptable.
