What I tend to do to share uassets with other people, on different computers is. first create a blank starter project, name it whatever main asset you are planning to share. I then just migrate the asset(collection of characters, level, level sequence, BP, whatever) to this new blank project. I then zip the new project folder I just migrated to. And then send that .zip file to whomeever. And you avoid having to do any “import” step. Just unzip on the other end and open the project.
That way you make sure it grabs all the related and referenced assets that are connected to the main asset you are sharing(by using the migration tool), so you are not relinking materials, etc. on the other end.