Suspending Forefeiture of a Restricted Stock Grant?

Hi,

I have a startup client with an employee who is leaving. The employee received several restricted stock grants that are still subject to vesting. The terms of the RSPA provide for forefeiture of unvested shares if the employee leaves prior to completion of the vesting period. The departure is amicable and the board doesn't want to exercise its repurchase right but RSPA is clear that unvested shares that aren't repurchased are forefeited.  Can the board "suspend" the vesting provision in the event the employee returns as a consultant in the future?  The employee filed an 83(b) election each time. Would there be any adverse consequences to the company?  

Would appreciate any thoughts.

Thanks!