Adding 2fa to LastPass with 2fa active is exactly like adding a password to Lastpass there is no extra risk.
As for Lastpass breaches, unless someone had a really easy master PW (without 2fa) the passwords in the vault should be safe.
I never activate (or deactivate) auto fill I usually have multiple logins for sites so auto fill doesn't work for me anyway.
Biting the hand that feeds IT
