Control Center will allow you to cancel a batch processing task before it starts by deleting it from the queue, but if you delete a batch processing task while it is already processing, it will still finish in the background.
Vectorizing tasks are added to the queue on a per-drawing basis. This means that if you want to interrupt the vectorization of a scene, you can simply stop the batch processing service and clear the queue in Control Center. However, rendering tasks are added to the queue on a per-scene basis. Therefore, the only way to interrupt the rendering of a scene while it is currently rendering is by interrupting the Harmony process that is rendering the scene.
In a terminal, enter the following command:
$ pgrep tbprocess
The command will output the process ID (pid) of the batch processing service.
Enter the following command to kill all processes started by the batch processing service, which will end any current batch processing job. Replace <pid of tbprocess> with the process ID of the batch processing service, obtained with the previous command.
$ sudo pkill -SIGKILL -P <pid of tbprocess>