Is a payment contingent on a change in control subject to a substantial risk of forfeiture regardless of the change in control definition (knowing that there must be some risk)? In other words, if an agreement promises to pay an employee $x when there is a change in control, can we design the CIC defintion as we like or must it comply with the 409A CIC definition? We would like to use our own defintion and keep the payment a short-term deferral.

Yep, I think you can do that.

If the change in control definition consitutes a SRF and the payment is made within the short-term deferral period, the definition need not meet the 409A CIC definition because it would be a short-term deferral.