ISC Governance Connector: Error when requesting user level entitlements for an identity

We have configured a ISC Governance source in our tenant and want to use it as a loopback connector to manage user levels for our administrative identities. However, unless we first aggregate the identities, we get the below error when requesting a user level entitlement.


In our case, there is too many identities to aggregate normally (~350K) and the filtering options will not help to reduce the scope of aggregation due to the fact that there is no standard naming convention for our administrative identities. Is there any suggested workaround here?
Why does the ISC Governance connecto require the account (identity) to be aggregated first, should it not be able to just provision to the existing identity directly?

I recall encountering this issue before. If you think about it, it does makes sense: since the connector relies on an existing identity, the account must be aggregated before user-level access can be requested. As a workaround, you can use the ACTION tab to assign the user level as an admin.

Manual assignment of user levels defeats the purpose of the connector: being able to request user levels as entitlements and certify user levels as entitlements as well.