It would be helpful to be able to choose before existing Users when starting a new DB. At the moment new DB is created with default user and and all others have to be created manually again.
When importing an old database from Helium 11, your users are preserved.
New databases shouldn't need to be created if you already have one working in Helium 12, so I don't think this is a feature we will be able to implement.
What's the main reason behind creating a new database?
You are right this is nothing that has to do with daily use.
I started my collection new with Helium 12, so I don't relate to an elder version. But I decided to separate my collection in three parts: music, classic & audiobooks.
As I do a lot of testing (with everytime creating new database for it) thought it may be helpful to get existing users from a preset or something similar.
So it's nothing really urgent as usually one works with a one time created DB and its users.