Exchange Online Access and Authentication

Doing a project at the moment for a customer that has set up a greenfields Azure tenancy and wants it fully managed by One Identity. Azure sync is pretty much all good, but having some problems with Exchange Online.

Environment is a big issue, while Azure access to Graph seems to be okay, the access to download the Exchange RPS is a bit of a pain....especially when lower environments are a different domain from the proxy server. The job service is running as AD service account (which is appropriately restricted).

How have others gotten around proxy issues where security policy restricts internet access? WinHttp or IEConfig? Dynamically enabled/disabled as part of Sync Project's connection script?

Speaking of the last part, I found this piece of information in Exchange Online's documentation:

On October 13th, 2020 we will retire Basic Authentication for Remote PowerShell (RPS) in Exchange Online.

I see that v8.1 template still has Basic. What alternate target authentication option have people got working?

The v2 of the Exchange modules look much better, but they're still in preview.