Unfortunately we don't have a way to configure DST offset other than selecting the timezone. One method would be to script a config file push to the APs when DST happens to switch the timezone and then the timezone change on the AP will be pushed down to the SMs. Looks like you are using Maestro to do this, it should only need to be done on the AP which should help. This is a good idea for a Maestro feature to automatically do DST adjustment.