Sounds like your issue is with queuing up the data for import into the target. In my case, there's a AD group populated with computers. The service account doing the adoption has local admin rights on those exact computers. Couldn't have a better basis for the underlying target used for agent adoption!
There is an issue where it is sometimes the case that the device hasn't been discovered but is still able to be adopted. In this situation, one can't add a hostname to a target but one can add the IP. All manageable. I'm working with Teemu on a solution for using BAS with the target. If interested, and if he agrees since he's the one mostly doing this, we can share.
I have attached an example of a business adapter which populates an inventory target from an excel spreadsheet containing a list of server names.
The business adapter process
1. Clears the existing target list
2. Populates a staging table from the spreadsheet contents
3. Repopulates the target from the spreadsheet list of servers
I am using this automation to support the need to remotely inventory XenDesktop parents which is a pain to keep maintained for an organization our size.
You can reuse this for different purposes just remember I hardcoded the insert to the BeaconTargetDiscoveredDeviceMapping_MT table columns TenantID and Include to value of 1. This may need to be updated for your purposes. Any other changes needed for the business adapter xml are in <> brackets.
Please don't critique my work too much I didn't spend much time on this. It does work nice though.
Nice work @dsalter.
One word of caution: the UI in FNMS is designed for and work best as long as you don't have too many individual devices/IP addresses recorded in a target. You shouldn't have too many problems with say some 10s of devices in a target, which is what you can reasonably configure using the UI. If you happened to create a target with say 100s or 1000s of devices in it using some sort of direct manipulation of records in the database like the approach discussed above, then the UI may struggle to cope.