Does anyone use these settings?

We do, however we have received negative feedback but cannot get seller support to acknowledge there own policy which states as follows:

With SSA enabled, your account health is protected from negative feedback due to late deliveries, and we will suppress negative feedback related to late deliveries on your SSA orders, as long as:

You shipped the orders on time

You provided valid tracking information

At ship confirm, you used a shipping service that matches (or is faster than) the service that was used by SSA used to calculate delivery promise. You can see what method was used on Order Detail page and Order API.

The order was shipped domestically.

We have opened multiple cases but we keep getting referred to Feedback Manager which isnt relevant for these orders shipped through SSA.

Ridiculously poor again from Amazon, SS do not even know the policy exists and quite clearly doesnt protect your account at all.