AAD Connect OU Filtering

Question

We have a sizable directory and I'm interested in filtering the SYSTEM OU for our AAD connect configuration.
I have performed some searches and am not seeing where this is a question that has come up.
We currently have ~30,000 objects in our SYSTEM OU, and from previous experience, there should not be anything needed from this location in the cloud. Can anybody provide some information regarding the relevance of syncing the SYSTEM OU and if local customizations (Possible Examples?) in the directory would require this OU's objects in O365?

Answer 1

AADConnect only syncs "identity objects"
https://github.com/MicrosoftDocs/azure-docs/blob/main/articles/active-directory/hybrid/concept-azure-ad-connect-sync-architecture.md

with some exceptions:
https://learn.microsoft.com/en-us/azure/active-directory/hybrid/concept-azure-ad-connect-sync-user-and-contacts

So unless you have identities in that system OU ( and not AD Config objects) , nothing will be synced from it.

This is the default config that will be sycned:
https://learn.microsoft.com/en-us/azure/active-directory/hybrid/concept-azure-ad-connect-sync-default-configuration