There's no such thing as a profile pic update. There's just a kind 0 event, so if you block updates, you block any change to the profile.

You would have to locally cache the pic and then never clear the cache (which is a bug, not a feature, sorry), list the NIP-05 next to the handle in the notes (easiest fix), or use NIP-81 (which is work to implement, but has the most long-term potential).