Cant answer that but to have unsupported UI config implemented there is one more way.
You can try one more thing.
Disconnet the IAP from Central by unassigning the license.
Delete the IAP from Central's AP down list.
Network mgmt>monitroing>AP>list>r go to right and use trash can to delete it.
Verify its disconnected from Central on IAP by running show ap debug cloud-server.
Now you can go into conf t and implement changes. commit apply and wr mem.
Now add the IAP into Central. Ideally IAP should come in unprovisioned section. From there you can take the IAP and its config and create a new UI group using it.
This way the CLI config you implemented will stay preserved.