Shared Mailbox: get correct FROM and email tracking at the same time

I have a shared mailbox that needs to (a) send with the correct FROM address by default, and (b) have email tracked to Salesforce via the Outlook Integration add-in. 

What I tried so far:

1. Auto-mapped shared mailbox — Tracking works, but users must manually select the shared mailbox in the From field every time; Outlook doesn't default to it. Too easy to send under the wrong identity by mistake.
2. Shared folder (delegate access) — Same FROM problem as above, no improvement.
3. Manually added as a second full account — Fixes the FROM problem; Outlook correctly defaults to the shared address in that context. But the Salesforce add-in no longer connects at all in that context, so nothing gets tracked.

It's a known limitation that shared mailboxes won't work with the add-in. What are the options left then? What's the best setup possible in this situation?