How to update config on AD Connect staging mode server

Question

We will updating the user sign in method from Pass through authentication (PTA) to Password hash synchronization and also adding a new forest to the ADConnect configuration. I have couple of question sin regards to that:

1. Will the users that are already authenticated have an outage while the password hash synchronisation is happening from on-prem to Azure AD as we have large user base and sync can take some time?
2. When we change the config on the staging mode server (secondary ADConnect server) do we need to take it out of staging mode and put the primary on staging OR can we just make these config changes on staging mode server while keeping it in staging mode and not syncing?

Answer 1

1. Should be no impact. See: https://techcommunity.microsoft.com/t5/microsoft-entra-azure-ad/migration-from-pta-to-phs/m-p/1489065
2. You make the changes on both the staging and active AADConnect servers. No need to to take the current staging server out of staging mode.