Hmmm, how about the following take.

We create alt accounts of popular accounts. We can see their content without opening any other platform.

This could give already a user base to these accounts on nostr, making the switch easier.

Usually the problem is social graph. If we rebuild without them, the switch will be easier.

It is not this easy. But I just wanted to share a different purpose for mirroring content. 

Maybe bad idea.