You have to be very careful when editing an active automation, because it is very easy to make a small mistake and end up with multiple leads unintentionally entering or leaving the workflow, or even receiving the wrong email—and these actions are irreversible.
How are leads affected by changes made to the automation steps?
The short answer to this question is: It depends on whether the change was made to a step that occurs before or after the step where the lead is at the time the change is made. For example:
In the above case, let's assume there is a lead that is at the standby step. If steps prior to the standby step are changed, the lead that is already at a later step will not be affected in any way. If steps after the standby step where the lead is at are changed and the workflow saved, then the lead will go through the updated steps where the changes were made.
If the standby step, where the lead is at, is deleted and the workflow saved, the lead will wait for the entire duration of the deleted waiting period, then continue the workflow with the next step.