Question about Skype for Business Online Address Book

1. What AD fields is the user replicator look for to populate RTCab databases in SfB online? Are there any required fields for an account to show up in Address book web query.

2. If I need to hide certain accounts based on an AD attribute from showing up the SfB online address book for my tenant is that possible to do?

3. Is there any ABSconfig tool available to manage the SfB online address book filtering?‎ I can't exclude these users from Azure AD sync because they use Sharepoint Online but don't use SfB so need a way to hide them from the SfB AB websearch.

I opened a premiere case (REG:116110414893424) and they said it's not possible‎ to do so but want to confirm this. This is holding up a major project for me so please Help!!