I'm not the person you asked, but the most relevant advice I got was to pay half the commission after month 1 and half after month 12.

It helps weed out the less honest people, aligns sales with support, and protects cash flow.

At a small company you would ideally have engineering involved before any contracts were signed.

At a large company you generally pass the sale off to a integration team who isn't commission based. And that team will quickly find out if the customer was badly lied to, And you will have time to cancel the commission.