Ok, it seems that the option of activating Tor for .onion relays is the bare minimum we should do.
The question is now, as a project, do we want to offer more privacy straight out of the box or not.
I am leaning towards also using Tor for:
1. Relays gathered from the Outbox model that are not in the user's relay list.
2. All relays that require Auth (no IP-Pubkey link)
3. All DM relays
By default.
More ideas are welcome.