BuddyPress.org

hi Eric

Yes, It is possible, but Unique header plugin handles it differently, It allows users to change Images on each individual posts page too.

Do you simply want the users to be able to change the header image for their blog not for individual articles page, if yes, I will look into it and remove some codes, that will make it happen.

But I think, perhaps the bp-default theme allows that too, not yet tested for individual blogs though.