The log tab in the HTML5 interface is filled with __item_stack entries when my workflows are running making it hard to see any of the logging I'm doing. Is there any way to hide all that noise?
The short answer is: no.
I think these entries are used as some kind of markers and so they cannot be removed from the log files, although it should be possible to filter them out when showing the log entries in the UI. But such filtering code is currently not there.