You actually CAN reverse-engineer running policy into the EMS-format policy.

Current array configuration can be exported from array node's registry to XML using script with root.ConnectToLocalStorage. Then this XML file after some modifications can be successfully imported to CSS.

I tested this method after the only TMG EMS server was lost and no configuration backup was available.

I described it in details here ant-sh.blogspot.com/.../retrieve-current-TMG-configuration-from-array-node-registry.html