Hi Steven M,

I am sorry for the delay of this reply.

One thing that has not migrated is the profile avatars and cover images. I suspect that it has something to do with the connection with the Amazon S3 bucket.

This is actually the default behaviour there the migration will only migrate image files that are side in your server. Anyway, in the next release, we will show a notice message if system detected you have images that are currently hosted in amazon S3

Anyway, I can see how to change the default profile cover image, but I am wondering if I change that, will it push a change out to all members of the community, or will it just be available for new members when they join?

Regarding the above, provided if the existing user are using default cover image, and if you override the EasySocial default cover image via template overriding, this will affect your existing users as well as your new users However, this will not affect your existing users who has their own cover image uploaded previously.

Hope this help and have a nice day!