Yes, in general that is possible.
If a setting is not supposed to be changed in an active run of a story, the system wil make it impossible to do so and show an error message or overlay about it.
That being said, there are a few things to take into consideration when changing anything in an active story:
- the changes will be active instantly the moment the editing person clicks to save
- changes in waiting nodes ("Wait" and "RT trigger") will only be applied to new users that arrive at these nodes, not for users that are already waiting in them when the changes are made
- if nodes get deleted while users are currently processed in them (e.g. arriving at them, dispatching at the moment or waiting there), then they will exit the story and won't continue
- the user count will not be acurate anymore if nodes get added or the context changes - it is recommended to reset the user count for any significant changes