- This had to be done as get_all_as_vector() cannot be customized by
scripts, and if an inherited UserManager needs to set up UserModules
this will cause issues later down the line.
- Other solutions like a user_setup() method could also work, but then
that would cause more individual (non-optimizable) lookups to db-based
backends (and likely others too), so this solution seems to be the best
currently.