We have automated systems to deal with requests in that category, it would probably have to be in the double-digit percentage of our customer base before we see any significant impact on our ability to conduct business.

We know which dat belongs to which customer, we know which data we must delete if requested, we know which data (eg invoice related for bookkeeping) we must keep even if requested to delete personal data.

If we ever piss off such a large portion of our customers, that they want to delete their accounts, GDPR-related requests will be the least of our concern.