Active Directory Fallback

I have a customer with a central AD server that we are authenticating multiple remote sites against. The problem is that when the remote sites loose internet/ VPN back to the AD server, then my users can’t authenticate normally.

I know the AD Fallback Cache exists but it doesn’t work on Ignition where the primary Gateway for the system is at the remote site.

Is there an easy way to cache the user source? Or could IA add that feature to the AD user sources?