What happens if I cancel?

Everything AutoPPC has done is a change you approved and uploaded to your own Amazon account. Those changes stay. Nothing is reverted, nothing is disabled, and no capability is withdrawn from your campaigns.

Your Amazon account keeps its state. Your history is retained after cancellation and remains available to export; you can request deletion at any time.

Export your history first if you want to keep it, and revoke the Amazon authorisation in Seller Central when you are done.