Dan,
You could do it for single variable, multiple rest calls as well but like I mentioned I do not know the full scope of all of your changes to each REST call.
If you were going to use the for loop script method, you would use curl so the body (in xml) would be in the single line. For example see a few queries from this KB Article:
Is it possible to override the speed of an interfa - CA Knowledge
An example of a CURL command to acquire the Interface list in the example above:
curl --header "Content-Type: application/xml" --request POST --data '<FilterSelect xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="filter.xsd"><Filter><DeviceComponent.DeviceItemID type="CONTAINS">4810</DeviceComponent.DeviceItemID></Filter><Select use="exclude" isa="exclude"><Item use="include"><Name use="include"/></Item></Select></FilterSelect>' --url http://DAhostname:8581/rest/ports/filtered
An example of a CURL command to make the change in the example above:
curl --header "Content-Type: application/xml" --request PUT --data '<Port version="1.0.0"><SpeedOutOverride>1.2E8</SpeedOutOverride><SpeedInOverride>1.2E8</SpeedInOverride></Port>' --url http://DAhostname:8581/rest/ports/4830
That being said, if you are trying to move over 200 discover profiles, it may be easier to mow through them manually as it may take you longer than expected to set of a scripting solution and REST is the only alternative to using the GUI.
Troy