You could submit this as a request, remember that a Dynamic IP will not be restored during a reboot. The Thin client will request a new one so given that it takes about 8 seconds for a reboot I would just use Rapport to reboot all the clients and get the new IP.
If you are doing a subnet change use Rapport to shutdown all the terminals before the new subnet addressing is put in place. The Workgroup version of Rapport to do all this is free.
-TT