Sorry I do not really understand what you want. If you don't process the PCN then you just create a mess in your warehouse and within a few days you will not be able to do anything normal, you will just jump from one error fixing to the next.
Example: you post from quality to unrestricted in MM. If you do not process the PCN, then you still have quality stock in WM along with negative quality stock and positive unrestricted stock in an interim storage type. Does that sound healthy?
Processing can be setup to run automatically with a batch job.
But this is usually a phase 2 of project, after anybody is clear with the processes and knows what steps has to be taken. Then you can sit together and define which steps could be executed in batch. But the people have to be ready to monitor all the batch runs, must be able to perform an activity manually in case the batch run failed.