Do you know that the product version is out of support? If there is no special reason to keep this one you should consider upgrading.
Indeed, if WFA is not connected the backup options, except for local, should not be even available.
If I recall correctly we do not have the setting to throttle directly. There is an option for a transfer policy which of course uses the ones defined in ONTAP. If you have specific requirements you need to configure the policies and select them in UM.