Yes, there is a buffer of 30 minutes before the end of the maintenance window. This buffer helps ensure that the post-patching tasks will run within the active maintenance window.
Pre-Patching Tasks - If a pre-patching task starts to execute on an endpoint before the buffer window, JetPatch will complete that task, even if that task takes longer than the buffer window to execute, but it won't start the next pre-patching tasks or the patching activities and will go directly to post-patching tasks, depending on the configuration.
Patching Tasks - If a patching task starts to execute on an endpoint before the buffer window, the task will terminate itself and will return the current results. JetPatch will execute post-patching tasks based on the patching results and the configuration.
Post-Patching Tasks - Post-patching tasks will run, regardless of the maintenance window. In other words, if JetPatch starts to execute the post-patching tasks, it will ignore the maintenance window limits and will make sure all post-patching tasks are executed.